譛ｬ鬆√�逶ｮ谺｡ 逶ｮ谺｡

11 蠑� (Expressions)

11.1 蝓ｺ譛ｬ蠑� (Primary Expressions)

Syntax
PrimaryExpression :
this
Identifier
Literal
ArrayLiteral
ObjectLiteral
( Expression )

11.1.1 this 繧ｭ繝ｼ繝ｯ繝ｼ繝� (this Keyword)

this 繧ｭ繝ｼ繝ｯ繝ｼ繝峨�螳溯｡後さ繝ｳ繝�く繧ｹ繝医� this 蛟､繧定ｩ穂ｾ｡縺吶ｋ縲�

11.1.2 隴伜挨蟄仙盾辣ｧ (Identifier Reference)

隴伜挨蟄舌�縲�繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 10.1.4 縺ｧ霑ｰ縺ｹ縺溘せ繧ｳ繝ｼ繝苓ｦ丞援繧剃ｽｿ逕ｨ縺励※隧穂ｾ｡縺輔ｌ繧九€ゅ％縺ｮ隴伜挨蟄占ｩ穂ｾ｡縺ｮ邨先棡縺ｯ蟶ｸ縺ｫ Reference 蝙九�蛟､縺ｧ縺ゅｋ縲�

11.1.3 繝ｪ繝�Λ繝ｫ蜿ら� (Literal Reference)

繝ｪ繝�Λ繝ｫ縺ｯ繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 7.8 縺ｫ霑ｰ縺ｹ繧九ｈ縺�↓隧穂ｾ｡縺輔ｌ繧九€�

11.1.4 Array 蛻晄悄蛹門ｭ� (Array Initialiser)

Array 蛻晄悄蛹門ｭ舌�縲� Array 繧ｪ繝悶ず繧ｧ繧ｯ繝医�蛻晄悄蛹悶ｒ險倩ｿｰ縺吶ｋ蠑上〒縲√Μ繝�Λ繝ｫ蠖｢蠑上〒譖ｸ縺九ｌ繧九€ゅ◎繧後�驟榊�隕∫ｴ�繧偵≠繧峨ｏ縺� 0 蛟倶ｻ･荳翫�蠑上�繝ｪ繧ｹ繝医〒縲√◎繧後◇繧瑚ｧ呈峡蠑ｧ "[ ]" 縺ｧ蝗ｲ縺ｾ繧後ｋ縲りｦ∫ｴ�縺ｯ繝ｪ繝�Λ繝ｫ縺ｧ縺ゅｋ蠢�ｦ√�縺ｪ縺�; 縺昴ｌ繧峨� Array 蛻晄悄蛹門ｭ舌′隧穂ｾ｡縺輔ｌ繧句ｺｦ縺ｫ隧穂ｾ｡縺輔ｌ繧九€�

驟榊�隕∫ｴ�縺ｯ隕∫ｴ�繝ｪ繧ｹ繝医�髢句ｧ九€∽ｸｭ髢薙€∵忰蟆ｾ縺ｧ逵∫払繧ゅ〒縺阪ｋ縲りｦ∫ｴ�繝ｪ繧ｹ繝井ｸｭ縺ｧ AssignmentExpression 縺ｮ蜈郁｡後＠縺ｪ縺�き繝ｳ繝槭�縲∵ｬ�縺代◆驟榊�隕∫ｴ�縺� Array 縺ｮ髟ｷ縺輔↓蟇�ｸ弱＠縲∫ｶ壹￥隕∫ｴ�縺ｮ繧､繝ｳ繝�ャ繧ｯ繧ｹ繧貞｢怜刈縺輔○繧九€ら怐逡･縺輔ｌ縺滄�蛻苓ｦ∫ｴ�縺ｯ螳夂ｾｩ縺輔ｌ縺ｪ縺�€�

Syntax
ArrayLiteral :
[ Elisionopt ]
[ ElementList ]
[ ElementList , Elisionopt ]
ElementList :
Elisionopt AssignmentExpression
ElementList , Elisionopt AssignmentExpression
Elision :
,
Elision ,
Semantics

逕滓�隕丞援 ArrayLiteral : [ Elisionopt ] 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. 蠑� new Array() 縺ｨ蜷梧ｧ倥↓縲∵眠隕上↓驟榊�繧堤函謌舌☆繧九€�
  2. Elision 繧定ｩ穂ｾ｡; 蟄伜惠縺励↑縺代ｌ縺ｰ縲∵焚蛟､ 0 繧堤畑縺�ｋ縲�
  3. Result(1) 縺ｮ [[Put]] 繝｡繧ｽ繝�ラ繧偵€∝ｼ墓焚 "length" 縺ｨ Result(2) 縺ｧ蜻ｼ蜃ｺ縺吶€�
  4. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 ArrayLiteral : [ ElementList ] 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. ElementList 繧定ｩ穂ｾ｡縲�
  2. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 ArrayLiteral : [ ElementList , Elisionopt ] 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. ElementList 繧定ｩ穂ｾ｡縲�
  2. Elision 繧定ｩ穂ｾ｡; 蟄伜惠縺励↑縺代ｌ縺ｰ縲∵焚蛟､ 0 繧堤畑縺�ｋ縲�
  3. Result(1) 縺ｮ [[Get]] 繝｡繧ｽ繝�ラ繧偵€∝ｼ墓焚 "length" 縺ｧ蜻ｼ蜃ｺ縺吶€�
  4. Result(1) 縺ｮ [[Put]] 繝｡繧ｽ繝�ラ繧偵€∝ｼ墓焚 "length" 縺ｨ (Result(2)+Result(3)) 縺ｧ蜻ｼ蜃ｺ縺吶€�
  5. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 ElementList : Elisionopt AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. 蠑� new Array() 縺ｨ蜷梧ｧ倥↓縲∵眠隕上↓驟榊�繧堤函謌舌☆繧九€�
  2. Elision 繧定ｩ穂ｾ｡; 蟄伜惠縺励↑縺代ｌ縺ｰ縲∵焚蛟､ 0 繧堤畑縺�ｋ縲�
  3. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(1) 縺ｮ [[Put]] 繝｡繧ｽ繝�ラ繧偵€∝ｼ墓焚 Result(2) 縺ｨ Result(4) 縺ｧ蜻ｼ蜃ｺ縺吶€�
  6. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 ElementList : ElementList , Elisionopt AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. ElementList 繧定ｩ穂ｾ｡縲�
  2. Elision 繧定ｩ穂ｾ｡; 蟄伜惠縺励↑縺代ｌ縺ｰ縲∵焚蛟､ 0 繧堤畑縺�ｋ縲�
  3. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(1) 縺ｮ [[Get]] 繝｡繧ｽ繝�ラ繧偵€∝ｼ墓焚 "length" 縺ｧ蜻ｼ蜃ｺ縺吶€�
  6. Result(1) 縺ｮ [[Put]] 繝｡繧ｽ繝�ラ繧偵€∝ｼ墓焚 (Result(2)+Result(5)) 縺ｨ Result(4) 縺ｧ蜻ｼ蜃ｺ縺吶€�
  7. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 Elision : , 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. 謨ｰ蛟､ 1 繧定ｿ斐☆縲�

逕滓�隕丞援 Elision : Elision , 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. Elision 繧定ｩ穂ｾ｡縲�
  2. (Result(1)+1) 繧定ｿ斐☆縲�

11.1.5 繧ｪ繝悶ず繧ｧ繧ｯ繝亥�譛溷喧蟄� (Object Initialiser)

繧ｪ繝悶ず繧ｧ繧ｯ繝亥�譛溷喧蟄舌� Object 縺ｮ蛻晄悄蛹悶ｒ險倩ｿｰ縺吶ｋ蠑上〒縺ゅｊ縲√Μ繝�Λ繝ｫ縺ｮ繧医≧縺ｪ蠖｢蠑上〒譖ｸ縺九ｌ繧九€ゅ�繝ｭ繝代ユ繧｣蜷阪→縺昴�蛟､縺ｮ 0 蛟倶ｻ･荳翫�邨��繝ｪ繧ｹ繝医ｒ { } 縺ｧ蝗ｲ繧€縲ょ€､縺ｯ繝ｪ繝�Λ繝ｫ縺ｧ縺ゅｋ蠢�ｦ√�縺ｪ縺�; 繧ｪ繝悶ず繧ｧ繧ｯ繝亥�譛溷喧蟄舌′隧穂ｾ｡縺輔ｌ繧句ｺｦ縺ｫ縲√◎繧後�隧穂ｾ｡縺輔ｌ繧九€�

Syntax
ObjectLiteral :
{ }
{ PropertyNameAndValueList }
PropertyNameAndValueList :
PropertyName : AssignmentExpression
PropertyNameAndValueList , PropertyName : AssignmentExpression
PropertyName :
Identifier
StringLiteral
NumericLiteral
Semantics

逕滓�隕丞援 ObjectLiteral : { } 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. 蠑� new Object() 縺ｨ蜷梧ｧ倥↓譁ｰ隕上↓繧ｪ繝悶ず繧ｧ繧ｯ繝医ｒ逕滓�縺吶ｋ縲�
  2. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 ObjectLiteral : { PropertyNameAndValueList } 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. PropertyNameAndValueList 繧定ｩ穂ｾ｡縲�
  2. Result(1) 繧定ｿ斐☆;

逕滓�隕丞援 PropertyNameAndValueList : PropertyName : AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. 蠑� new Object() 縺ｨ蜷梧ｧ倥↓譁ｰ隕上↓繧ｪ繝悶ず繧ｧ繧ｯ繝医ｒ逕滓�縺吶ｋ縲�
  2. PropertyName 繧定ｩ穂ｾ｡縲�
  3. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(1) 縺ｮ [[Put]] 繝｡繧ｽ繝�ラ繧偵€∝ｼ墓焚 Result(2) 縺ｨ Result(4) 縺ｧ蜻ｼ蜃ｺ縺吶€�
  6. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 PropertyNameAndValueList : PropertyNameAndValueList , PropertyName : AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. PropertyNameAndValueList 繧定ｩ穂ｾ｡縲�
  2. PropertyName 繧定ｩ穂ｾ｡縲�
  3. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(1) 縺ｮ [[Put]] 繝｡繧ｽ繝�ラ繧偵€∝ｼ墓焚 Result(2) 縺ｨ Result(4) 縺ｧ蜻ｼ蜃ｺ縺吶€�
  6. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 PropertyName : Identifier 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. Identifier 縺ｨ蜷後§譁�ｭ励す繝ｼ繧ｱ繝ｳ繧ｹ縺ｧ讒区�縺輔ｌ繧区枚蟄怜�繝ｪ繝�Λ繝ｫ繧貞ｽ｢謌舌☆繧九€�
  2. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 PropertyName : StringLiteral 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. StringLiteral 縺ｮ蛟､繧定ｿ斐☆縲�

逕滓�隕丞援 PropertyName : NumericLiteral 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. NumericLiteral 縺ｮ蛟､繧貞ｽ｢謌舌☆繧九€�
  2. ToString(Result(1)) 繧定ｿ斐☆縲�

11.1.6 繧ｰ繝ｫ繝ｼ繝怜喧貍皮ｮ怜ｭ� (The Grouping Operator)

逕滓�隕丞援 PrimaryExpression : ( Expression ) 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. Expression 繧定ｩ穂ｾ｡縲ゅ％繧後� Reference 蝙九〒繧ゅｈ縺�€�
  2. Result(1) 繧定ｿ斐☆縲�

NOTE 縺薙�繧｢繝ｫ繧ｴ繝ｪ繧ｺ繝�縺ｯ縲� Result(1) 縺ｫ GetValue 繧帝←逕ｨ縺励↑縺�€� delete 繧� typeof 縺ｮ繧医≧縺ｪ貍皮ｮ怜ｭ舌↓諡ｬ蠑ｧ縺ｮ縺､縺�◆蠑上ｒ驕ｩ逕ｨ縺ｧ縺阪ｋ繧医≧縺ｫ縺吶ｋ縺薙→縺後％繧後↓縺､縺�※縺ｮ荳ｻ縺ｪ蜍墓ｩ溘〒縺ゅｋ縲�

11.2 蟾ｦ霎ｺ蠑� (Left-Hand-Side Expressions)

Syntax
MemberExpression :
PrimaryExpression
FunctionExpression
MemberExpression [ Expression ]
MemberExpression . Identifier
new MemberExpression Arguments
NewExpression :
MemberExpression
new NewExpression
CallExpression :
MemberExpression Arguments
CallExpression Arguments
CallExpression [ Expression ]
CallExpression . Identifier
Arguments :
( )
( ArgumentList )
ArgumentList :
AssignmentExpression
ArgumentList , AssignmentExpression
LeftHandSideExpression :
NewExpression
CallExpression

11.2.1 繝励Ο繝代ユ繧｣繧｢繧ｯ繧ｻ繧ｹ貍皮ｮ怜ｭ� (Property Accessors)

繝峨ャ繝郁ｨ俶ｳ輔ｒ逕ｨ縺�※縲√�繝ｭ繝代ユ繧｣縺ｯ蜷榊燕縺ｫ繧医ｊ繧｢繧ｯ繧ｻ繧ｹ縺輔ｌ繧�:

MemberExpression . Identifier
CallExpression . Identifier

縺ｾ縺溘�諡ｬ蠑ｧ險俶ｳ輔〒:

MemberExpression [ Expression ]
CallExpression [ Expression ]

繝峨ャ繝郁ｨ俶ｳ輔�谺｡縺ｮ讒区枚逧�､画鋤縺ｧ隱ｬ譏弱＆繧後ｋ:

MemberExpression . Identifier

縺ｮ謖ｯ繧玖�縺��谺｡縺ｨ蜷檎ｭ峨〒縺ゅｋ縲�

MemberExpression [ <identifier-string> ]

蜷梧ｧ倥↓

CallExpression . Identifier

縺ｮ謖ｯ繧玖�縺��谺｡縺ｨ蜷檎ｭ峨〒縺ゅｋ縲�

CallExpression [ <identifier-string> ]

<identifier-string> 縺ｮ縺ｨ縺薙ｍ縺ｯ Identifier 縺ｨ縺励※蜷後§譁�ｭ励す繝ｼ繧ｱ繝ｳ繧ｹ繧呈ｧ区�縺吶ｋ譁�ｭ怜�繝ｪ繝�Λ繝ｫ縺ｧ縺ゅｋ縲�

逕滓�隕丞援 MemberExpression : MemberExpression [ Expression ] 縺ｯ谺｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. MemberExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. Expression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. ToObject(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. ToString(Result(4)) 繧貞他蜃ｺ縺吶€�
  7. 蝓ｺ貅悶が繝悶ず繧ｧ繧ｯ繝医′ Result(5) 縺ｧ繝励Ο繝代ユ繧｣蜷阪′ Result(6) 縺ｧ縺ゅｋ Reference 蝙九�蛟､繧定ｿ斐☆縲�

逕滓�隕丞援 CallExpression : CallExpression [ Expression ] 縺ｯ蜈ｨ縺丞酔縺俶婿豕輔〒隧穂ｾ｡縺輔ｌ繧九′縲√せ繝�ャ繝� 1 縺ｧ縺ｯ CallExpression 縺瑚ｩ穂ｾ｡縺輔ｌ繧九€�

11.2.2 new 貍皮ｮ怜ｭ� (The new Operator)

逕滓�隕丞援 NewExpression : new NewExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. NewExpression 繧定ｩ穂ｾ｡縺吶ｋ縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. Type(Result(2)) 縺� Object 縺ｧ縺ｪ縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  4. Result(2) 縺悟�驛ｨ [[Construct]] 繝｡繧ｽ繝�ラ繧貞ｮ溯｣�＠縺ｪ縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  5. 蠑墓焚縺ｪ縺励〒 Result(2) 縺ｮ [[Construct]] 繝｡繧ｽ繝�ラ繧貞他蜃ｺ縺吶€�(蠑墓焚蛟､縺ｫ遨ｺ繝ｪ繧ｹ繝医ｒ謠蝉ｾ帙☆繧九€�)
  6. Result(5) 繧定ｿ斐☆縲�

逕滓�隕丞援 MemberExpression : new MemberExpression Arguments 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. MenberExpression 繧定ｩ穂ｾ｡縺吶ｋ縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. 蜀�Κ縺ｫ蠑墓焚蛟､繝ｪ繧ｹ繝医ｒ謖√▽ Arguments 繧定ｩ穂ｾ｡縺吶ｋ縲�
  4. Type(Result(2)) 縺� Object 縺ｧ縺ｪ縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  5. Result(2) 縺悟�驛ｨ [[Construct]] 繝｡繧ｽ繝�ラ繧貞ｮ溯｣�＠縺ｪ縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  6. Result(2) 縺ｮ [[Construct]] 繝｡繧ｽ繝�ラ繧貞他縺ｳ縲∝ｼ墓焚蛟､縺ｫ繝ｪ繧ｹ繝� Result(3) 繧呈署萓帙☆繧九€�
  7. Result(6) 繧定ｿ斐☆縲�

11.2.3 髢｢謨ｰ蜻ｼ蜃ｺ縺� (Function Calls)

逕滓�隕丞援 CallExpression : MemberExpression Arguments 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. MemberExpression 繧定ｩ穂ｾ｡縲�
  2. Arguments 繧定ｩ穂ｾ｡縺励€∝ｼ墓焚蛟､縺ｮ蜀�Κ List 繧堤函謌舌☆繧九€�(繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.2.4)縲�
  3. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  4. Type(Result(3)) 縺� Object 縺ｧ縺ｪ縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  5. Result(3) 縺悟�驛ｨ [[Call]] 繝｡繧ｽ繝�ラ繧貞ｮ溯｣�＠縺ｪ縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  6. Type(Result(1)) 縺� Reference 縺ｪ繧峨�縲� Result(6) 縺ｯ GetBase(Result(1)) 縲ゅ◎縺�〒縺ｪ縺代ｌ縺ｰ縲� Result(6) 縺ｯ null 縲�
  7. Result(6) 縺� Activation 繧ｪ繝悶ず繧ｧ繧ｯ繝医↑繧峨�縲� Result(7) 縺ｯ null 縲ゅ◎縺�〒縺ｪ縺代ｌ縺ｰ縲� Result(7) 縺ｯ Result(6) 縺ｨ蜷後§縲�
  8. Result(3) 縺ｮ [[Call]] 繝｡繧ｽ繝�ラ繧貞他縺ｳ縲》his 蛟､縺ｫ Result(7) 縲∝ｼ墓焚蛟､縺ｫ繝ｪ繧ｹ繝� Result(2) 繧呈ｸ｡縺吶€�
  9. Result(8) 繧定ｿ斐☆縲�

逕滓�隕丞援 CallExpression : CallExpression Arguments 縺ｯ蜈ｨ縺丞酔讒倥↓隧穂ｾ｡縺輔ｌ繧九′縲√せ繝�ャ繝� 1 縺ｧ縺ｯ CallExpression 縺瑚ｩ穂ｾ｡縺輔ｌ繧九€�

NOTE Result(3) 縺� Native ECMAScript 繧ｪ繝悶ず繧ｧ繧ｯ繝医↑繧峨�縲� Result(8) 縺ｯ縺代＠縺ｦ Reference 蝙九↓縺ｯ縺ｪ繧峨↑縺�€� Host 繧ｪ繝悶ず繧ｧ繧ｯ繝亥他縺ｳ蜃ｺ縺励′ Reference 蝙九�蛟､繧定ｿ斐☆縺九←縺�°縺ｯ縲∝ｮ溯｣�ｾ晏ｭ倥〒縺ゅｋ縲�

11.2.4 蠑墓焚繝ｪ繧ｹ繝� (Argument Lists)

蠑墓焚繝ｪ繧ｹ繝医�隧穂ｾ｡縺ｯ蛟､縺ｫ繧医ｋ蜀�Κ逧�Μ繧ｹ繝� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 8.8) 繧堤函謌舌☆繧九€�

逕滓�隕丞援 Arguments : ( ) 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. 蛟､縺ｫ繧医ｋ遨ｺ縺ｮ蜀�Κ逧�Μ繧ｹ繝医ｒ霑斐☆縲�

逕滓�隕丞援 Arguments : ( ArgumentList ) 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. ArgumentList 繧定ｩ穂ｾ｡縲�
  2. Result(1) 繧定ｿ斐☆縲�

逕滓�隕丞援 ArgumentList : AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. 蜚ｯ荳€縺ｮ鬆�岼縺� Result(2) 縺ｧ縺ゅｋ蜀�Κ逧�Μ繧ｹ繝医ｒ霑斐☆縲�

逕滓�隕丞援 ArgumentList : ArgumentList , AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. ArgumentList 繧定ｩ穂ｾ｡縲�
  2. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  3. GetValue(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. Result(1) 繧医ｊ 1 螟ｧ縺阪＞髟ｷ縺輔€ヽesult(1) 縺ｮ鬆�岼縺ｮ譛ｫ蟆ｾ縺ｫ Result(3) 繧堤ｶ壹￠縺滄��岼繧呈戟縺､縲∵眠縺励＞蜀�Κ逧�Μ繧ｹ繝医ｒ霑斐☆縲�

11.2.5 髢｢謨ｰ蠑� (Function Expressions)

逕滓�隕丞援 MemberExpression : FunctionExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. FunctionExpression 繧定ｩ穂ｾ｡縲�
  2. Result(1) 繧定ｿ斐☆縲�

11.3 蠕檎ｽｮ蠑� (Postfix Expressions)

Syntax
PostfixExpression :
LeftHandSideExpression
LeftHandSideExpression [LineTerminator 辟｡縺余 ++
LeftHandSideExpression [LineTerminator 辟｡縺余 --

11.3.1 蠕檎ｽｮ蠅怜�貍皮ｮ怜ｭ� (Postfix Increment Operator)

逕滓�隕丞援 PostfixExpression : LeftHandSideExpression [no LineTerminator here] ++ 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. LeftHandSideExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. + 貍皮ｮ怜ｭ舌→蜷後§隕丞援縺ｧ (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.6.3)縲ヽesult(3) 縺ｫ蛟､ 1 繧貞刈縺医ｋ縲�
  5. PutValue(Result(1), Result(4)) 繧貞他蜃ｺ縺吶€�
  6. Result(3) 繧定ｿ斐☆縲�

11.3.2 蠕檎ｽｮ貂帛�貍皮ｮ怜ｭ� (Postfix Decrement Operator)

逕滓�隕丞援 PostfixExpression : LeftHandSideExpression [no LineTerminator here] -- 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. LeftHandSideExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. - 貍皮ｮ怜ｭ舌→蜷後§隕丞援 (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.6.3) 縺ｧ縲� Result(3) 縺九ｉ蛟､ 1 繧貞ｼ輔￥縲�
  5. PutValue(Result(1), Result(4)) 繧貞他蜃ｺ縺吶€�
  6. Result(3) 繧定ｿ斐☆縲�

11.4 蜊倬��ｼ皮ｮ怜ｭ� (Unary Operators)

Syntax
UnaryExpression :
PostfixExpression
delete UnaryExpression
void UnaryExpression
typeof UnaryExpression
++ UnaryExpression
-- UnaryExpression
+ UnaryExpression
- UnaryExpression
~ UnaryExpression
! UnaryExpression

11.4.1 delete 貍皮ｮ怜ｭ� (The delete Operator)

逕滓�隕丞援 UnaryExpression : delete UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. Type(Result(1)) 縺� Reference 縺ｧ縺ｪ縺代ｌ縺ｰ縲� true 繧定ｿ斐☆縲�
  3. GetBase(Result(1)) 繧貞他蜃ｺ縺吶€�
  4. GetPropertyName(Result(1)) 繧貞他蜃ｺ縺吶€�
  5. Result(3) 縺ｮ [[Delete]] 繝｡繧ｽ繝�ラ繧貞他縺ｳ縲∝炎髯､縺吶ｋ繝励Ο繝代ユ繧｣蜷阪→縺励※ Result(4) 繧呈ｸ｡縺吶€�
  6. Result(5) 繧定ｿ斐☆縲�

11.4.2 void 貍皮ｮ怜ｭ� (The void Operator)

逕滓�隕丞援 UnaryExpression : void UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. undefined 繧定ｿ斐☆縲�

11.4.3 typeof 貍皮ｮ怜ｭ� (The typeof Operator)

逕滓�隕丞援 UnaryExpression : typeof UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. Type(Result(1)) 縺� Reference 縺ｧ縺ｪ縺代ｌ縺ｰ縲� 繧ｹ繝�ャ繝� 4 縺ｸ縲�
  3. GetBase(Result(1)) 縺� null 縺ｪ繧峨�縲� "undefined" 繧定ｿ斐☆縲�
  4. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  5. 谺｡縺ｮ陦ｨ縺ｫ縺励◆縺後▲縺ｦ縲� Type(Result(4)) 縺九ｉ豎ｺ螳壹＆繧後ｋ譁�ｭ怜�繧定ｿ斐☆:
Type Result
Undefined "undefined"
Null "object"
Boolean "boolean"
Number "number"
String "string"
Object (native and doesn't implement [[Call]]) "object"
Object (native and implements [[Call]]) "function"
Object (host) Implementation-dependent

11.4.4 蜑咲ｽｮ蠅怜�貍皮ｮ怜ｭ� (Prefix Increment Operator)

逕滓�隕丞援 UnaryExpression : ++ UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. + 貍皮ｮ怜ｭ舌→蜷後§隕丞援 (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.6.3) 縺ｧ縲� Result(3) 縺ｫ蛟､ 1 繧貞刈縺医ｋ縲�
  5. PutValue(Result(1), Result(4)) 繧貞他蜃ｺ縺吶€�
  6. Result(4) 繧定ｿ斐☆縲�

11.4.5 蜑咲ｽｮ貂帛�貍皮ｮ怜ｭ� (Prefix Decrement Operator)

逕滓�隕丞援 UnaryExpression : -- UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. - 貍皮ｮ怜ｭ舌→蜷後§隕丞援 (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.6.3) 縺ｧ縲� Result(3) 縺九ｉ蛟､ 1 繧貞ｼ輔￥縲�
  5. PutValue(Result(1), Result(4)) 繧貞他蜃ｺ縺吶€�
  6. Result(4) 繧定ｿ斐☆縲�

11.4.6 蜊倬�� + 貍皮ｮ怜ｭ� (Unary + Operator)

蜊倬�� + 貍皮ｮ怜ｭ舌�鬆�ｒ Number 蝙九↓螟画鋤縺吶ｋ縲�

逕滓�隕丞援 UnaryExpression : + UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. Result(3) 繧定ｿ斐☆縲�

11.4.7 蜊倬�� - 貍皮ｮ怜ｭ� (Unary - Operator)

蜊倬�� - 貍皮ｮ怜ｭ舌�鬆�ｒ Number 蝙九↓螟画鋤縺励€∝渚霆｢縺吶ｋ縲� +0 縺ｮ蜷ｦ螳壹� -0縲� -0 縺ｮ蜷ｦ螳壹� +0 繧堤函謌舌☆繧九％縺ｨ縺ｫ豕ｨ諢上€�

逕滓�隕丞援 UnaryExpression : - UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. Result(3) 縺� NaN 縺ｪ繧峨�縲� NaN 繧定ｿ斐☆縲�
  5. Result(3) 縺ｮ蜷ｦ螳�; 縺､縺ｾ繧翫€∝酔縺伜､ｧ縺阪＆縺ｧ隨ｦ蜿ｷ縺碁€��謨ｰ繧堤ｮ怜�縺吶ｋ縲�
  6. Result(5) 繧定ｿ斐☆縲�

11.4.8 繝薙ャ繝亥凄螳壽ｼ皮ｮ怜ｭ� (Bitwise NOT Operator) ( ~ )

逕滓�隕丞援 UnaryExpression : ~ UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToInt32(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. Result(3) 縺ｫ繝薙ャ繝郁｣懈焚繧帝←逕ｨ縺吶ｋ縲らｵ先棡縺ｯ隨ｦ蜿ｷ莉倥″ 32 繝薙ャ繝域紛謨ｰ縺ｧ縺ゅｋ縲�
  5. Result(4) 繧定ｿ斐☆縲�

11.4.9 隲也炊蜷ｦ螳壽ｼ皮ｮ怜ｭ� (Logical NOT Operator) ( ! )

逕滓�隕丞援 UnaryExpression : ! UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. UnaryExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToBoolean(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. Result(3) 縺� true 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  5. true 繧定ｿ斐☆縲�

11.5 蜑ｰ髯､貍皮ｮ怜ｭ� (Multiplicative Operators)

Syntax
MultiplicativeExpression :
UnaryExpression
MultiplicativeExpression * UnaryExpression
MultiplicativeExpression / UnaryExpression
MultiplicativeExpression % UnaryExpression
Semantics

@ 繧剃ｸ翫↓螳夂ｾｩ縺輔ｌ繧区ｼ皮ｮ怜ｭ舌�荳€縺､縺ｨ縺励※縲∫函謌占ｦ丞援 MultiplicativeExpression : MultiplicativeExpression @ UnaryExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. MultiplicativeExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. UnaryExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. ToNumber(Result(4)) 繧貞他蜃ｺ縺吶€�
  7. Result(5) 縺ｨ Result(6) 縺ｫ縲∵欠螳壹＆繧後◆貍皮ｮ� (*, /, %) 繧帝←逕ｨ縺吶ｋ縲ゆｸ玖ｨ倥�繝弱�繝� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.5.1, 11.5.2, 11.5.3) 繧貞盾辣ｧ縲�
  8. Result(7) 繧定ｿ斐☆縲�

11.5.1 * 貍皮ｮ怜ｭ舌�驕ｩ逕ｨ (Applying the * Operator)

  • 貍皮ｮ怜ｭ舌�荵礼ｮ励ｒ陦後＞縲����遨阪ｒ逕滓�縺吶ｋ縲ゆｹ礼ｮ励�蜿ｯ謠帷噪縺ｧ縺ゅｋ縲よ怏髯先焚邊ｾ蠎ｦ? ( finite precision ) 縺ｮ縺溘ａ縲� ECMAScript 縺ｫ縺翫＞縺ｦ縲∽ｹ礼ｮ励�蟶ｸ縺ｫ邨仙粋逧�↑繧上￠縺ｧ縺ｯ縺ｪ縺�€�

豬ｮ蜍募ｰ乗焚轤ｹ謨ｰ荵礼ｮ励�邨先棡縺ｯ縲� IEEE 754 蛟咲ｲｾ蠎ｦ險育ｮ苓ｦ丞援縺ｫ繧医ｊ豎ｺ螳壹＆繧後ｋ:

  • 縺ｩ縺｡繧峨°縺ｮ鬆�′ NaN 縺ｪ繧峨�縲∫ｵ先棡縺ｯ NaN 縺ｧ縺ゅｋ縲�
  • 邨先棡縺ｮ隨ｦ蜿ｷ縺ｯ縲∽ｸ｡譁ｹ縺ｮ鬆�′蜷後§隨ｦ蜿ｷ繧呈戟縺､縺ｪ繧峨�豁｣隨ｦ蜿ｷ縺ｧ縺ゅｊ縲∫焚縺ｪ繧狗ｬｦ蜿ｷ繧呈戟縺､縺ｪ繧峨�雋�隨ｦ蜿ｷ縺ｧ縺ゅｋ縲�
  • 0 縺ｫ繧医ｋ辟｡髯仙､ｧ縺ｮ荵礼ｮ励�邨先棡縺ｯ縲� NaN 縺ｫ縺ｪ繧九€�
  • 辟｡髯仙､ｧ縺ｫ繧医ｋ辟｡髯仙､ｧ縺ｮ荵礼ｮ励�邨先棡縺ｯ縲� infinity 縺ｧ縺ゅｋ縲らｬｦ蜿ｷ縺ｯ 荳翫↓縺ゅ￡縺溯ｦ丞援縺ｧ豎ｺ螳壹☆繧九€�
  • 0 莉･螟悶�譛蛾剞謨ｰ縺ｫ繧医ｋ辟｡髯仙､ｧ縺ｮ荵礼ｮ励�邨先棡縺ｯ縲∫ｬｦ蜿ｷ莉倥″辟｡髯仙､ｧ縺ｧ縺ゅｋ縲らｬｦ蜷医�荳翫↓縺ゅ￠縺溯ｦ丞援縺ｧ豎ｺ螳壹☆繧九€�
  • 辟｡髯仙､ｧ縺ｧ繧� 0 縺ｧ繧� NaN 縺ｧ繧ゅ↑縺�ｮ九ｊ縺ｮ繧ｱ繝ｼ繧ｹ縺ｧ縺ｯ縲∫ｩ阪′邂怜�縺輔ｌ縲� IEEE 754 逶ｴ霑代∈縺ｮ荳ｸ繧√Δ繝ｼ繝峨ｒ菴ｿ逕ｨ縺励※縲∫峩霑代�陦ｨ迴ｾ蜿ｯ閭ｽ縺ｪ蛟､縺ｸ荳ｸ繧√ｉ繧後ｋ縲ょ､ｧ縺阪＆縺瑚｡ｨ縺帙↑縺�⊇縺ｩ螟ｧ縺阪＞縺ｪ繧峨�縲∵ｼ皮ｮ励�繧ｪ繝ｼ繝舌�繝輔Ο繝ｼ縺励€∫ｵ先棡縺ｯ驕ｩ蛻�↑隨ｦ蜷医�辟｡髯仙､ｧ縺ｨ縺ｪ繧九€ょ､ｧ縺阪＆縺瑚｡ｨ縺帙↑縺�⊇縺ｩ蟆上＆縺�ｉ縺ｰ縲∵ｼ皮ｮ励�繧｢繝ｳ繝€繝ｼ繝輔Ο繝ｼ縺礼ｵ先棡縺ｯ驕ｩ蛻�↑隨ｦ蜷医� 0 縺ｨ縺ｪ繧九€� ECMAScript 險€隱槭�縲� IEEE 754 縺ｫ螳夂ｾｩ縺輔ｌ繧区ｮｵ髫守噪繧｢繝ｳ繝€繝ｼ繝輔Ο繝ｼ (gradual underflow) 縺ｮ繧ｵ繝昴�繝医ｒ蠢��医→縺吶ｋ縲�

11.5.2 / 貍皮ｮ怜ｭ舌�驕ｩ逕ｨ (Applying the / Operator)

/ 貍皮ｮ怜ｭ舌�荵礼ｮ励ｒ陦後＞縲����蝠�ｒ逕滓�縺吶ｋ縲ょｷｦ鬆�′陲ｫ髯､謨ｰ縺ｧ蜿ｳ鬆�′髯､謨ｰ縺ｧ縺ゅｋ縲� ECMAScript 縺ｯ謨ｴ謨ｰ髯､邂励ｒ陦後ｏ縺ｪ縺�€る��→髯､邂玲ｼ皮ｮ礼ｵ先棡縺ｮ蜈ｨ縺ｦ縺ｯ蛟咲ｲｾ蠎ｦ豬ｮ蜍募ｰ乗焚轤ｹ謨ｰ縺ｧ縺ゅｋ縲ゆｹ礼ｮ励�邨先棡縺ｯ縲� IEEE 754 邂苓｡楢ｦ丞ｮ壹↓繧医ｊ豎ｺ螳壹＆繧後ｋ:

  • 縺ｩ縺｡繧峨°縺ｮ鬆�′ NaN 縺ｪ繧峨�縲∫ｵ先棡縺ｯ NaN 縺ｧ縺ゅｋ縲�
  • 邨先棡縺ｮ隨ｦ蜿ｷ縺ｯ縲∽ｸ｡譁ｹ縺ｮ鬆�′蜷後§隨ｦ蜿ｷ繧呈戟縺､縺ｪ繧峨�豁｣隨ｦ蜿ｷ縺ｧ縺ゅｊ縲∫焚縺ｪ繧狗ｬｦ蜿ｷ繧呈戟縺､縺ｪ繧峨�雋�隨ｦ蜿ｷ縺ｧ縺ゅｋ縲�
  • 辟｡髯仙､ｧ縺ｮ辟｡髯仙､ｧ縺ｫ繧医ｋ髯､邂励�邨先棡縺ｯ縲� NaN 縺ｧ縺ゅｋ縲�
  • 辟｡髯仙､ｧ縺ｮ 0 縺ｫ繧医ｋ髯､邂励�邨先棡縺ｯ縲∫┌髯仙､ｧ縺ｫ縺ｪ繧九€らｬｦ蜿ｷ縺ｯ 荳翫↓縺ゅ￡縺溯ｦ丞援縺ｧ豎ｺ螳壹☆繧九€�
  • 辟｡髯仙､ｧ縺ｮ 0 莉･螟悶�譛蛾剞謨ｰ縺ｫ繧医ｋ髯､邂励�邨先棡縺ｯ縲∫ｬｦ蜿ｷ莉倥″辟｡髯仙､ｧ縺ｧ縺ゅｋ縲らｬｦ蜷医�荳翫↓縺ゅ￠縺溯ｦ丞援縺ｧ豎ｺ螳壹☆繧九€�
  • 譛蛾剞謨ｰ縺ｮ辟｡髯仙､ｧ縺ｫ繧医ｋ髯､邂励�邨先棡縺ｯ縲� 0 縺ｧ縺ゅｋ縲らｬｦ蜷医�荳翫↓縺ゅ￠縺溯ｦ丞援縺ｧ豎ｺ螳壹☆繧九€�
  • 0 縺ｮ 0 縺ｫ繧医ｋ髯､邂励�邨先棡縺ｯ縲� NaN 縺ｧ縺ゅｋ; 0 縺ｮ莉ｻ諢上�莉悶�譛蛾剞謨ｰ縺ｫ繧医ｋ髯､邂励�邨先棡縺ｯ 0 縺ｧ縺ゅｋ縲らｬｦ蜷医�荳翫↓縺ゅ￠縺溯ｦ丞援縺ｧ豎ｺ螳壹☆繧九€�
  • 0 莉･螟悶�譛蛾剞謨ｰ縺ｮ 0 繧医ｋ髯､邂励�邨先棡縺ｯ縲∫ｬｦ蜿ｷ莉倥″辟｡髯仙､ｧ縺ｧ縺ゅｋ縲らｬｦ蜷医�荳翫↓縺ゅ￠縺溯ｦ丞援縺ｧ豎ｺ螳壹☆繧九€�
  • 辟｡髯仙､ｧ縺ｧ繧� 0 縺ｧ繧� NaN 縺ｧ繧ゅ↑縺�ｮ九ｊ縺ｮ繧ｱ繝ｼ繧ｹ縺ｧ縺ｯ縲∝膚縺檎ｮ怜�縺輔ｌ縲� IEEE 754 逶ｴ霑代∈縺ｮ荳ｸ繧√Δ繝ｼ繝峨ｒ菴ｿ逕ｨ縺励※縲∫峩霑代�陦ｨ迴ｾ蜿ｯ閭ｽ縺ｪ蛟､縺ｸ荳ｸ繧√ｉ繧後ｋ縲ょ､ｧ縺阪＆縺瑚｡ｨ縺帙↑縺�⊇縺ｩ螟ｧ縺阪＞縺ｪ繧峨�縲∵ｼ皮ｮ励�繧ｪ繝ｼ繝舌�繝輔Ο繝ｼ縺礼ｵ先棡縺ｯ驕ｩ蛻�↑隨ｦ蜷医�辟｡髯仙､ｧ縺ｨ縺ｪ繧九€ょ､ｧ縺阪＆縺瑚｡ｨ縺帙↑縺�⊇縺ｩ蟆上＆縺�ｉ縺ｰ縲∵ｼ皮ｮ励�繧｢繝ｳ繝€繝ｼ繝輔Ο繝ｼ縺礼ｵ先棡縺ｯ驕ｩ蛻�↑隨ｦ蜷医� 0 縺ｨ縺ｪ繧九€� ECMAScript 險€隱槭�縲� IEEE 754 縺ｫ螳夂ｾｩ縺輔ｌ繧区ｮｵ髫守噪繧｢繝ｳ繝€繝ｼ繝輔Ο繝ｼ (gradual underflow) 縺ｮ繧ｵ繝昴�繝医ｒ蠢��医→縺吶ｋ縲�

11.5.3 % 貍皮ｮ怜ｭ舌�驕ｩ逕ｨ (Applying the % Operator)

% 貍皮ｮ怜ｭ舌�縲∬ｨ€螟悶�髯､邂励°繧蛾���蜑ｰ菴吶ｒ邂怜�縺吶ｋ; 蟾ｦ鬆�′陲ｫ髯､謨ｰ縺ｧ蜿ｳ鬆�′髯､謨ｰ縺ｧ縺ゅｋ縲�

NOTE C 縺翫ｈ縺ｳ C++ 縺ｫ縺翫＞縺ｦ縲∝臆菴呎ｼ皮ｮ怜ｭ舌�謨ｴ謨ｰ鬆��縺ｿ繧貞女縺台ｻ倥￠繧�; ECMAScript 縺ｫ縺翫＞縺ｦ縺ｯ縲∵ｵｮ蜍募ｰ乗焚轤ｹ謨ｰ鬆�ｂ蜿励￠莉倥￠繧九€�

% 貍皮ｮ怜ｭ舌↓繧医ｊ邂怜�縺輔ｌ繧九ｈ縺�↑豬ｮ蜍募ｰ乗焚轤ｹ謨ｰ縺ｮ蜑ｰ菴呎ｼ皮ｮ励�邨先棡縺ｯ縲� IEEE 754 縺ｧ螳夂ｾｩ縺輔ｌ繧� "reminder" 貍皮ｮ励→蜷梧ｧ倥〒縺ｯ縺ｪ縺�€� IEEE 754 "remainder" 貍皮ｮ励�縲∝�繧頑昏縺ｦ髯､邂� (truncating division) 縺九ｉ縺ｧ縺ｯ縺ｪ縺丈ｸｸ繧�勁邂� (rounding division) 縺九ｉ蜑ｰ菴吶ｒ邂怜�縺励€√＠縺溘′縺｣縺ｦ縺昴�謖ｯ繧玖�縺��譛臥畑縺ｪ謨ｴ謨ｰ蜑ｰ菴呎ｼ皮ｮ怜ｭ舌�縺昴ｌ縺ｨ縺ｯ鬘樔ｼｼ縺励↑縺�€ゆｻ｣繧上ｊ縺ｫ ECMAScript 險€隱槭� % 繧呈ｵｮ蜍募ｰ乗焚轤ｹ謨ｰ貍皮ｮ嶺ｸ翫〒螳夂ｾｩ縺励€� Java 謨ｴ謨ｰ蜑ｰ菴呎ｼ皮ｮ怜ｭ舌�縺昴ｌ縺ｫ鬘樔ｼｼ縺吶ｋ譁ｹ豕輔〒謖ｯ繧玖�縺�; 縺薙ｌ縺ｯ C 繝ｩ繧､繝悶Λ繝ｪ髢｢謨ｰ fmod 縺ｨ豈碑ｼ�＆繧後ｋ.

ECMAScript 豬ｮ蜍募ｰ乗焚轤ｹ謨ｰ蜑ｰ菴呎ｼ皮ｮ励�邨先棡縺ｯ縲� IEEE 邂苓｡薙�隕丞援縺ｧ豎ｺ螳壹＆繧後ｋ:

  • 縺ｩ縺｡繧峨°縺ｮ鬆�′ NaN 縺ｪ繧峨�縲∫ｵ先棡縺ｯ NaN 縺ｧ縺ゅｋ縲�
  • 邨先棡縺ｮ隨ｦ蜿ｷ縺ｯ縲∬｢ｫ髯､謨ｰ縺ｮ隨ｦ蜿ｷ縺ｨ遲峨＠縺�€�
  • 陲ｫ髯､謨ｰ縺檎┌髯仙､ｧ縲√∪縺溘�髯､謨ｰ縺� 0 縲� 縺ゅｋ縺��縺昴�荳｡譁ｹ縺ｪ繧峨�縲� 邨先棡縺ｯ NaN 縺ｧ縺ゅｋ縲�
  • 陲ｫ髯､謨ｰ縺梧怏髯先焚 縺九▽ 髯､謨ｰ縺檎┌髯仙､ｧ縺ｪ繧峨�縲∫ｵ先棡縺ｯ陲ｫ髯､謨ｰ縺ｨ遲峨＠縺�€�
  • 陲ｫ髯､謨ｰ縺� 0 縺九▽ 髯､謨ｰ縺梧怏髯先焚縺ｪ繧峨�縲∫ｵ先棡縺ｯ陲ｫ髯､謨ｰ縺ｨ蜷後§縺ｧ縺ゅｋ縲�
  • 辟｡髯仙､ｧ縺ｧ繧� 0 縺ｧ繧� NaN 縺ｧ繧ゅ↑縺�ｮ九ｊ縺ｮ繧ｱ繝ｼ繧ｹ縺ｧ縺ｯ縲∬｢ｫ髯､謨ｰ n 縺ｨ髯､謨ｰ d 縺九ｉ豬ｮ蜍募ｰ乗焚轤ｹ謨ｰ縺ｮ蜑ｰ菴� r 縺ｯ縲∵焚蟄ｦ逧�未菫� r = n - ( d * q ) 縺ｫ繧医▲縺ｦ螳夂ｾｩ縺輔ｌ繧九€� q 縺ｯ謨ｴ謨ｰ縺ｧ n/d 縺瑚ｲ�縺ｪ繧芽ｲ�縲∵ｭ｣縺ｪ繧峨�豁｣縺ｧ縺ゅｊ縲∝､ｧ縺阪＆縺ｯ n 縺ｨ d 縺ｮ逵溘�謨ｰ蟄ｦ逧�↑蝠��螟ｧ縺阪＆繧定ｶ�∴縺ｪ縺�庄閭ｽ縺ｪ髯舌ｊ螟ｧ縺阪＞縲�

11.6 蜉�貂帶ｼ皮ｮ怜ｭ� (Additive Operators)

Syntax
AdditiveExpression :
MultiplicativeExpression
AdditiveExpression + MultiplicativeExpression
AdditiveExpression - MultiplicativeExpression

11.6.1 蜉�豕墓ｼ皮ｮ怜ｭ� (The Addition operator) ( + )

蜉�豕墓ｼ皮ｮ怜ｭ舌�縲∵枚蟄怜�縺ｮ騾｣邨舌€√∪縺溘�謨ｰ縺ｮ蜉�豕輔�縺�★繧後°繧定｡後≧縲�

逕滓�隕丞援 AdditiveExpression : AdditiveExpression + MultiplicativeExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. AdditiveExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. MultiplicativeExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. ToPrimitive(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. ToPrimitive(Result(4)) 繧貞他蜃ｺ縺吶€�
  7. Type(Result(5)) 縺� String 縺ｾ縺溘� Type(Result(6)) 縺� String 縺ｪ繧峨�縲� 繧ｹ繝�ャ繝� 12 縺ｸ縲� (縺薙�繧ｹ繝�ャ繝励�縲�未菫よｼ皮ｮ怜ｭ舌�豈碑ｼ�い繝ｫ繧ｴ繝ｪ繧ｺ繝�縺ｮ繧ｹ繝�ャ繝� 3 縺ｨ縺ｯ逡ｰ縺ｪ繧翫€� 縺九▽ 縺ｧ縺ｯ縺ｪ縺� 縺ｾ縺溘� 縺ｧ縺ゅｋ縺薙→縺ｫ豕ｨ諢上€�)
  8. ToNumber(Result(5)) 繧貞他蜃ｺ縺吶€�
  9. ToNumber(Result(6)) 繧貞他蜃ｺ縺吶€�
  10. Result(8) 縺ｨ Result(9) 縺ｫ縲∝刈豕墓ｼ皮ｮ励ｒ驕ｩ逕ｨ縺吶ｋ縲ゆｸ玖ｨ倥ヮ繝ｼ繝亥盾辣ｧ (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.6.3)縲�
  11. Result(10) 繧定ｿ斐☆縲�
  12. ToString(Result(5)) 繧貞他蜃ｺ縺吶€�
  13. ToString(Result(6)) 繧貞他蜃ｺ縺吶€�
  14. Result(12) 縺ｫ Result(13) 繧帝€｣邨舌☆繧九€�
  15. Result(14) 繧定ｿ斐☆縲�

NOTE 繧ｹ繝�ャ繝� 5 縺ｨ 6 縺ｫ縺翫￠繧� ToPrimitive 蜻ｼ蜃ｺ縺励〒縺ｯ繝偵Φ繝医ｒ謠蝉ｾ帙＠縺ｪ縺�€ょ�繝阪う繝�ぅ繝� ECMAScript 繧ｪ繝悶ず繧ｧ繧ｯ繝医� Date 繧ｪ繝悶ず繧ｧ繧ｯ繝医ｒ髯､縺阪€√ヲ繝ｳ繝医�谺�螯ゅｒ繝偵Φ繝� Number 縺御ｸ弱∴繧峨ｌ縺溘ｈ縺�↓謇ｱ縺�; Date 繧ｪ繝悶ず繧ｧ繧ｯ繝医�縲√ヲ繝ｳ繝医�谺�螯ゅｒ繝偵Φ繝� String 縺御ｸ弱∴繧峨ｌ縺溘ｈ縺�↓謇ｱ縺�€�

繝帙せ繝医が繝悶ず繧ｧ繧ｯ繝医�縲√ヲ繝ｳ繝医�谺�螯ゅｒ莉悶�譁ｹ豕輔〒謇ｱ縺｣縺ｦ繧医＞縲�

11.6.2 貂帶ｳ墓ｼ皮ｮ怜ｭ� (The Subtraction Operator) ( - )

逕滓�隕丞援 AdditiveExpression : AdditiveExpression - MultiplicativeExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. AdditiveExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. MultiplicativeExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. ToNumber(Result(4)) 繧貞他蜃ｺ縺吶€�
  7. Result(5) 縺ｨ Result(6) 縺ｫ縲∵ｸ帶ｳ墓ｼ皮ｮ励ｒ驕ｩ逕ｨ縺吶ｋ縲ゆｸ玖ｨ倥ヮ繝ｼ繝亥盾辣ｧ (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.6.3)縲�
  8. Result(7) 繧定ｿ斐☆縲�

11.6.3 蜉�貂帶ｼ皮ｮ怜ｭ舌�謨ｰ縺ｸ縺ｮ驕ｩ逕ｨ (Applying the Additive Operators ( +,- ) to Numbers)

謨ｰ蝙九� 2 蛟九�鬆�↓驕ｩ逕ｨ縺輔ｌ繧九→縺阪€� + 貍皮ｮ怜ｭ舌�蜉�豕輔ｒ陦後＞縲����蜥後ｒ逕滓�縺吶ｋ縲�

- 貍皮ｮ怜ｭ舌�貂帶ｳ輔ｒ陦後＞縲� 2 蛟九�謨ｰ鬆��蟾ｮ繧堤函謌舌☆繧九€�

蜉�豕輔�蜿ｯ謠帷噪貍皮ｮ� (commutative operation) 縺ｧ縺ゅｋ縺後€∝ｸｸ縺ｫ邨仙粋逧� (associative) 縺ｨ縺�≧縺薙→縺ｧ縺ｯ縺ｪ縺�€�

蜉�豕輔�邨先棡縺ｯ縲� IEEE 754 蛟咲ｲｾ蠎ｦ險育ｮ苓ｦ丞援繧剃ｽｿ逕ｨ縺励※豎ｺ螳壹＆繧後ｋ:

  • 縺ｩ縺｡繧峨�鬆�ｂ NaN 縺ｪ繧峨�縲∫ｵ先棡縺ｯ NaN 縺ｧ縺ゅｋ縲�
  • 逡ｰ隨ｦ蜿ｷ縺ｮ 2 蛟九�辟｡髯仙､ｧ縺ｮ蜥後�縲� NaN 縺ｧ縺ゅｋ縲�
  • 蜷檎ｬｦ蜿ｷ縺ｮ 2 蛟九�辟｡髯仙､ｧ縺ｮ蜥後�縲√◎縺ｮ隨ｦ蜿ｷ縺ｮ辟｡髯仙､ｧ縺ｧ縺ゅｋ縲�
  • 1 蛟九�辟｡髯仙､ｧ縺ｨ譛蛾剞謨ｰ縺ｮ蜥後�縲∫┌髯仙､ｧ縺ｮ鬆�→遲峨＠縺�€�
  • 2 蛟九�雋�隨ｦ蜿ｷ縺ｮ 0 縺ｮ蜥後�縲� -0 縺ｧ縺ゅｋ縲�2 蛟九�豁｣隨ｦ蜿ｷ縺ｮ 0縲√∪縺� 2 蛟九�逡ｰ隨ｦ蜿ｷ縺ｮ 0 縺ｮ蜥後�縲� +0 縺ｧ縺ゅｋ縲�
  • 0 縺ｨ 0 莉･螟悶�譛蛾剞謨ｰ縺ｮ蜥後�縲� 0 莉･螟悶�鬆�→遲峨＠縺�€�
  • 逡ｰ隨ｦ蜿ｷ縺ｧ蜷後§螟ｧ縺阪＆縺ｮ 2 蛟九� 0 莉･螟悶�譛蛾剞謨ｰ縺ｮ蜥後�縲� +0 縺ｧ縺ゅｋ縲�
  • 辟｡髯仙､ｧ縺ｧ繧� 0 縺ｧ繧� NaN 縺ｧ繧ゅ↑縺上€���′蜷檎ｬｦ蜿ｷ縺ｧ縺ゅｋ縺九∪縺溘�逡ｰ縺ｪ繧句､ｧ縺阪＆繧呈戟縺､谿九ｊ縺ｮ繧ｱ繝ｼ繧ｹ縺ｧ縺ｯ縲∝柱縺檎ｮ怜�縺輔ｌ縲� IEEE 754 逶ｴ霑代∈縺ｮ荳ｸ繧√Δ繝ｼ繝峨ｒ菴ｿ逕ｨ縺励※縲∫峩霑代�陦ｨ迴ｾ蜿ｯ閭ｽ縺ｪ蛟､縺ｸ荳ｸ繧√ｉ繧後ｋ. 螟ｧ縺阪＆縺瑚｡ｨ縺帙↑縺�⊇縺ｩ螟ｧ縺阪＞縺ｪ繧峨�縲∵ｼ皮ｮ励�繧ｪ繝ｼ繝舌�繝輔Ο繝ｼ縺励€∫ｵ先棡縺ｯ驕ｩ蛻�↑隨ｦ蜷医�辟｡髯仙､ｧ縺ｨ縺ｪ繧九€� ECMAScript 險€隱槭�縲� IEEE 754 縺ｫ螳夂ｾｩ縺輔ｌ繧区ｮｵ髫守噪繧｢繝ｳ繝€繝ｼ繝輔Ο繝ｼ (gradual underflow) 縺ｮ繧ｵ繝昴�繝医ｒ蠢��医→縺吶ｋ縲�

謨ｰ蝙九� 2 蛟九�鬆�↓驕ｩ逕ｨ縺輔ｌ繧九→縺阪€� - 貍皮ｮ怜ｭ舌�貂帶ｳ輔ｒ陦後＞縲����蟾ｮ繧堤函謌舌☆繧�; 蟾ｦ鬆�′陲ｫ貂帶焚縺ｧ縲∝承鬆�′貂帶焚縺ｧ縺ゅｋ縲よ焚鬆� a 縺ｨ b 繧剃ｸ弱∴繧峨ｌ繧九→縲∝ｸｸ縺ｫ a-b 縺ｯ a+(-b) 縺ｨ蜷後§邨先棡繧堤函謌舌☆繧九€�

11.7 繝薙ャ繝亥ｹ�す繝輔ヨ貍皮ｮ怜ｭ� (Bitwise Shift Operators)

Syntax
ShiftExpression :
AdditiveExpression
ShiftExpression << AdditiveExpression
ShiftExpression >> AdditiveExpression
ShiftExpression >>> AdditiveExpression

11.7.1 蟾ｦ繧ｷ繝輔ヨ貍皮ｮ怜ｭ� (The Left Shift Operator) ( << )

蜿ｳ鬆�〒謖�ｮ壹＆繧後ｋ驥上↓繧医ｊ縲∝ｷｦ鬆�ｸ翫↓繝薙ャ繝亥ｹ�ｷｦ繧ｷ繝輔ヨ貍皮ｮ励ｒ陦後≧縲�

逕滓�隕丞援 ShiftExpression : ShiftExpression << AdditiveExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. ShiftExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. AdditiveExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. ToInt32(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. ToUint32(Result(4)) 繧貞他蜃ｺ縺吶€�
  7. Result(6) 縺ｮ荳倶ｽ� 5 繝薙ャ繝井ｻ･螟悶ｒ繝槭せ繧ｯ縺吶ｋ縲� 縺､縺ｾ繧翫€� Result(6) & 0x1F 繧堤ｮ怜�縺吶ｋ縲�
  8. Result(5) 繧� Result(7) 繝薙ャ繝亥ｷｦ繧ｷ繝輔ヨ縺吶ｋ縲らｵ先棡縺ｯ隨ｦ蜿ｷ莉倥″ 32 繝薙ャ繝域紛謨ｰ縺ｧ縺ゅｋ縲�
  9. Result(8) 繧定ｿ斐☆縲�

11.7.2 隨ｦ蜿ｷ莉倥″蜿ｳ繧ｷ繝輔ヨ貍皮ｮ怜ｭ� (The Signed Right Shift Operator) ( >> )

蜿ｳ鬆�〒謖�ｮ壹＆繧後ｋ驥上↓繧医ｊ縲∝ｷｦ鬆�ｸ翫↓隨ｦ蜿ｷ繧剃ｼｴ縺�ン繝�ヨ蟷�承繧ｷ繝輔ヨ貍皮ｮ励ｒ陦後≧縲�

逕滓�隕丞援 ShiftExpression : ShiftExpression >> AdditiveExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. ShiftExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. AdditiveExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. ToInt32(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. ToUint32(Result(4)) 繧貞他蜃ｺ縺吶€�
  7. Result(6) 縺ｮ荳倶ｽ� 5 繝薙ャ繝井ｻ･螟悶ｒ繝槭せ繧ｯ縺吶ｋ縲� 縺､縺ｾ繧翫€� Result(6) & 0x1F 繧堤ｮ怜�縺吶ｋ縲�
  8. Result(5) 繧� Result(7) 繝薙ャ繝育ｬｦ蜿ｷ諡｡蠑ｵ蜿ｳ繧ｷ繝輔ヨ縺吶ｋ縲よ怙荳贋ｽ阪ン繝�ヨ縺ｯ莨晄眺縺吶ｋ縲らｵ先棡縺ｯ隨ｦ蜿ｷ莉倥″ 32 繝薙ャ繝域紛謨ｰ縺ｧ縺ゅｋ縲�
  9. Result(8) 繧定ｿ斐☆縲�

11.7.3 隨ｦ蜿ｷ縺ｪ縺怜承繧ｷ繝輔ヨ貍皮ｮ怜ｭ� (The Unsigned Right Shift Operator) ( >>> )

蜿ｳ鬆�〒謖�ｮ壹＆繧後ｋ驥上↓繧医ｊ縲∝ｷｦ鬆�ｸ翫↓ 0 繧剃ｼｴ縺�ン繝�ヨ蟷�承繧ｷ繝輔ヨ貍皮ｮ励ｒ陦後≧縲�

逕滓�隕丞援 ShiftExpression : ShiftExpression >>> AdditiveExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. ShiftExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. AdditiveExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. ToUint32(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. ToUint32(Result(4)) 繧貞他蜃ｺ縺吶€�
  7. Result(6) 縺ｮ荳倶ｽ� 5 繝薙ャ繝井ｻ･螟悶ｒ繝槭せ繧ｯ縺吶ｋ縲� 縺､縺ｾ繧翫€� Result(6) & 0x1F 繧堤ｮ怜�縺吶ｋ縲�
  8. Result(5) 繧� Result(7) 繝薙ャ繝亥�縺�縺� 0 諡｡蠑ｵ蜿ｳ繧ｷ繝輔ヨ縺吶ｋ縲らｩｺ繝薙ャ繝医� 0 縺ｧ蝓九ａ繧峨ｌ繧九€らｵ先棡縺ｯ隨ｦ蜿ｷ縺ｪ縺� 32 繝薙ャ繝域紛謨ｰ縺ｧ縺ゅｋ縲�
  9. Result(8) 繧定ｿ斐☆縲�

11.8 髢｢菫よｼ皮ｮ怜ｭ� (Relational Operators)

Syntax
RelationalExpression :
ShiftExpression
RelationalExpression < ShiftExpression
RelationalExpression > ShiftExpression
RelationalExpression <= ShiftExpression
RelationalExpression >= ShiftExpression
RelationalExpression instanceof ShiftExpression
RelationalExpression in ShiftExpression
RelationalExpressionNoIn :
ShiftExpression
RelationalExpressionNoIn < ShiftExpression
RelationalExpressionNoIn > ShiftExpression
RelationalExpressionNoIn <= ShiftExpression
RelationalExpressionNoIn >= ShiftExpression
RelationalExpressionNoIn instanceof ShiftExpression

NOTE NoIn 螟牙喧蠖｢縺ｯ縲’or 譁��荳ｭ縺ｮ in 貍皮ｮ怜ｭ舌ｒ蜷ｫ繧€髢｢菫ょｼ丞�縺ｮ in 貍皮ｮ怜ｭ舌�豺ｷ荵ｱ縺ｮ蝗樣∩縺ｫ蠢�ｦ√〒縺ゅｋ縲�

Semantics

髢｢菫よｼ皮ｮ怜ｭ舌�隧穂ｾ｡縺ｮ邨先棡縺ｯ蟶ｸ縺ｫ Boolean 蝙九〒縺ゅｊ縲∵ｼ皮ｮ怜ｭ舌↓蜷阪▼縺代ｉ繧後◆髢｢菫ゅ′縺昴� 2 鬆�俣縺ｫ邯ｭ謖√＆繧後※縺�ｋ縺九←縺�°繧貞渚譏�縺吶ｋ縲�

RelationalExpressionNoIn 逕滓�隕丞援縺ｯ RelationalExpression 逕滓�隕丞援縺ｨ蜷梧ｧ倥↓隧穂ｾ｡縺輔ｌ繧九′縲∝�驛ｨ縺ｮ RelationalExpression 縺ｮ莉｣繧上ｊ縺ｫ縲ヽelationalExpressionNoIn 縺瑚ｩ穂ｾ｡縺輔ｌ繧九€�

11.8.1 Less-than 貍皮ｮ怜ｭ� (The Less-than Operator) ( < )

逕滓�隕丞援 RelationalExpression : RelationalExpression < ShiftExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. RelationalExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ShiftExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. 豈碑ｼ� Result(2) < Result(4) 繧貞ｮ溯｡後☆繧九€� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.8.5.)
  6. Result(5) 縺� undefined 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲ゅ◎縺�〒縺ｪ縺代ｌ縺ｰ縲� Result(5) 繧定ｿ斐☆縲�

11.8.2 Grater-than 貍皮ｮ怜ｭ� (The Greater-than Operator) ( > )

逕滓�隕丞援 RelationalExpression : RelationalExpression > ShiftExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. RelationalExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ShiftExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. 豈碑ｼ� Result(4) < Result(2) 繧貞ｮ溯｡後☆繧九€� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.8.5.)
  6. Result(5) 縺� undefined 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲ゅ◎縺�〒縺ｪ縺代ｌ縺ｰ縲� Result(5) 繧定ｿ斐☆縲�

11.8.3 Less-than-or-equal 貍皮ｮ怜ｭ� (The Less-than-or-equal Operator) ( <= )

逕滓�隕丞援 RelationalExpression : RelationalExpression <= ShiftExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. RelationalExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ShiftExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. 豈碑ｼ� Result(4) < Result(2) 繧貞ｮ溯｡後☆繧� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.8.5.)
  6. Result(5) 縺� true 縺ｾ縺溘� undefined縺ｪ繧峨�縲� false 繧定ｿ斐☆縲ゅ◎縺�〒縺ｪ縺代ｌ縺ｰ縲� true 繧定ｿ斐☆縲�

11.8.4 Greater-than-or-equal 貍皮ｮ怜ｭ� (The Greater-than-or-equal Operator) ( >= )

逕滓�隕丞援 RelationalExpression : RelationalExpression >= ShiftExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. RelationalExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ShiftExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. 豈碑ｼ� Result(2) < Result(4) 繧貞ｮ溯｡後☆繧九€� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.8.5.)
  6. Result(5) 縺� true 縺ｾ縺溘� undefined 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲ゅ◎縺�〒縺ｪ縺代ｌ縺ｰ縲� true 繧定ｿ斐☆縲�

11.8.5 謚ｽ雎｡逧�未菫よｯ碑ｼ�い繝ｫ繧ｴ繝ｪ繧ｺ繝� (The Abstract Relational Comparison Algorithm)

x 縺ｨ y 繧貞€､縺ｨ縺励※縲∵ｯ碑ｼ� x < y 縺ｯ縲� true, false, 縺ｾ縺溘� undefined 繧堤函謌舌☆繧� (蟆代↑縺上→繧ゆｸ€譁ｹ縺ｮ鬆�′ NaN 縺ｧ縺ゅｋ縺薙→繧堤､ｺ縺�)縲� 縺薙�豈碑ｼ��谺｡縺ｮ繧医≧縺ｫ螳溯｡後＆繧後ｋ:

  1. ToPrimitive(x, hint Number) 繧貞他蜃ｺ縺吶€�
  2. ToPrimitive(y, hint Number) 繧貞他蜃ｺ縺吶€�
  3. If Type(Result(1)) 縺� String 縺九▽ Type(Result(2)) 縺� String 縺ｪ繧峨�縲√せ繝�ャ繝� 16 縺ｸ縲� (縺薙�繧ｹ繝�ャ繝励′ or 縺ｮ莉｣繧上ｊ縺ｫ and 繧剃ｽｿ縺�€∝刈豕墓ｼ皮ｮ怜ｭ� + 縺ｮ縺溘ａ縺ｮ繧｢繝ｫ繧ｴ繝ｪ繧ｺ繝�縺ｫ縺翫＞縺ｦ繧ｹ繝�ャ繝� 7 縺九ｉ逡ｰ縺ｪ繧九％縺ｨ縺ｫ豕ｨ諢上€�)
  4. ToNumber(Result(1)) 繧貞他蜃ｺ縺吶€�
  5. ToNumber(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. Result(4) 縺� NaN 縺ｪ繧峨�縲� undefined 繧定ｿ斐☆縲�
  7. Result(5) 縺� NaN 縺ｪ繧峨�縲� undefined 繧定ｿ斐☆縲�
  8. Result(4) 縺ｨ Result(5) 縺悟酔縺俶焚蛟､縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  9. Result(4) 縺� +0 縺九▽ Result(5) 縺� -0 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  10. Result(4) 縺� -0 縺九▽ Result(5) 縺� +0 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  11. Result(4) 縺� +竏� 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  12. Result(5) 縺� +竏� 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  13. Result(5) 縺� -竏� 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  14. Result(4) 縺� -竏� 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  15. Result(4) 縺ｮ謨ｰ蟄ｦ蛟､縺� Result(5) 縺ｮ謨ｰ蟄ｦ蛟､繧医ｊ蟆上＆縺代ｌ縺ｰ縲� true 繧定ｿ斐☆縲� -- 縺薙ｌ繧峨�謨ｰ蟄ｦ蛟､縺ｯ蜈ｱ縺ｫ譛蛾剞縺ｪ 0 莉･螟悶�蛟､縺ｧ縺ゅｋ縺薙→縺ｫ豕ｨ諢� -- 縺昴≧縺ｧ縺ｪ縺代ｌ縺ｰ縲� false 繧定ｿ斐☆縲�
  16. Result(2) 縺� Result(1) 縺ｮ謗･鬆ｭ霎槭↑繧峨�縲� false 繧定ｿ斐☆縲� (q 縺� p 縺ｨ莉悶�譁�ｭ怜� r 縺ｮ騾｣邨千ｵ先棡縺ｧ縺ゅｊ縺医ｋ縺ｪ繧峨�縲∵枚蟄怜�蛟､ p 縺ｯ譁�ｭ怜�蛟､ q 縺ｮ謗･鬆ｭ霎槭〒縺ゅｋ縲Ｓ 繧堤ｩｺ譁�ｭ怜�縺ｨ縺吶ｌ縺ｰ莉ｻ諢上�譁�ｭ怜�縺ｯ縺昴ｌ閾ｪ霄ｫ縺ｮ謗･鬆ｭ霎槭〒縺ゅｋ縺薙→縺ｫ豕ｨ諢上€�)
  17. Result(1) 縺� Result(2) 縺ｮ謗･鬆ｭ霎槭↑繧峨�縲� true 繧定ｿ斐☆縲�
  18. Result(1) 縺ｮ菴咲ｽｮ k 縺ｮ譁�ｭ励′ Result(2) 縺ｮ菴咲ｽｮ k 縺ｮ譁�ｭ励→逡ｰ縺ｪ繧九ｈ縺�↑雋�縺ｧ縺ｪ縺�怙蟆乗紛謨ｰ繧� k 縺ｨ縺吶ｋ縲� (縺ｩ縺｡繧峨�譁�ｭ怜�繧ゆｺ偵＞縺ｮ謗･鬆ｭ霎槭→縺ｪ繧峨↑縺�ｈ縺�↑ k 縺悟ｭ伜惠縺励↑縺代ｌ縺ｰ縺ｪ繧峨↑縺�€�)
  19. m 繧� Result(1) 縺ｮ菴咲ｽｮ k 縺ｮ譁�ｭ励�繧ｳ繝ｼ繝峨�繧､繝ｳ繝亥€､縺ｧ縺ゅｋ謨ｴ謨ｰ縺ｨ縺吶ｋ縲�
  20. n 繧� Result(2) 縺ｮ菴咲ｽｮ k 縺ｮ譁�ｭ励�繧ｳ繝ｼ繝峨�繧､繝ｳ繝亥€､縺ｧ縺ゅｋ謨ｴ謨ｰ縺ｨ縺吶ｋ縲�
  21. m < n 縺ｪ繧峨� true 繧定ｿ斐＠縲√◎縺�〒縺ｪ縺代ｌ縺ｰ縲� false 繧定ｿ斐☆縲�

NOTE 譁�ｭ怜�豈碑ｼ��縲∝腰邏斐↑霎樊嶌逧�ｺ丞�繧偵さ繝ｼ繝峨�繧､繝ｳ繝亥€､縺ｮ繧ｷ繝ｼ繧ｱ繝ｳ繧ｹ縺ｮ蛟､縺ｫ逕ｨ縺�ｋ縲よ枚蟄励ｄ譁�ｭ怜�縺ｮ遲我ｾ｡諤ｧ縲√♀繧医� Unicode 莉墓ｧ� 縺ｧ螳夂ｾｩ縺輔ｌ繧矩��ｺ上�辣ｧ蜷医�縲√％繧御ｻ･荳願､�尅縺ｧ諢丞袖隲也噪縺ｫ謖�髄縺励◆螳夂ｾｩ繧堤畑縺�ｋ隧ｦ縺ｿ縺ｯ縺ｪ縺�€ゅ◎繧後ｆ縺医€� Unicode 讓呎ｺ悶↓繧医▲縺ｦ隕乗ｺ也噪縺ｫ遲峨＠縺�枚蟄怜�縺御ｸ咲ｭ我ｾ｡縺ｨ讀懈渊縺輔ｌ繧九°繧ゅ＠繧後↑縺�€ょ柑譫懊↓縺翫＞縺ｦ縺薙�繧｢繝ｫ繧ｴ繝ｪ繧ｺ繝�縺ｯ縲∝曙譁ｹ縺ｮ譁�ｭ怜�縺梧里縺ｫ豁｣隕丞喧蠖｢蠑上〒縺ゅｋ縺薙→繧呈Φ螳壹☆繧九€�

11.8.6 instanceof 貍皮ｮ怜ｭ� (The instanceof operator)

逕滓�隕丞援 RelationalExpression: RelationalExpression instanceof ShiftExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. RelationalExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ShiftExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(4) 縺後が繝悶ず繧ｧ繧ｯ繝医〒縺ｪ縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  6. Result(4) 縺� [[HasInstance]] 繝｡繧ｽ繝�ラ繧呈戟縺溘↑縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  7. Result(4) 縺ｮ [[HasInstance]] 繝｡繧ｽ繝�ラ繧貞他縺ｳ縲√ヱ繝ｩ繝｡繝ｼ繧ｿ Result(2) 繧呈ｸ｡縺吶€�
  8. Result(7) 繧定ｿ斐☆縲�

11.8.7 in 貍皮ｮ怜ｭ� (The in operator)

逕滓�隕丞援 RelationalExpression : RelationalExpression in ShiftExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. RelationalExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ShiftExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(4) 縺後が繝悶ず繧ｧ繧ｯ繝医〒縺ｪ縺代ｌ縺ｰ縲∽ｾ句､� TypeError 繧呈兜縺偵ｋ縲�
  6. ToString(Result(2)) 繧貞他蜃ｺ縺吶€�
  7. Result(4) 縺ｮ [[HasProperty]] 繝｡繧ｽ繝�ラ繧貞他縺ｳ縲√ヱ繝ｩ繝｡繝ｼ繧ｿ縺ｫ Result(6) 繧呈ｸ｡縺吶€�
  8. Result(7) 繧定ｿ斐☆縲�

11.9 遲我ｾ｡貍皮ｮ怜ｭ� (Equality Operators)

Syntax
EqualityExpression :
RelationalExpression
EqualityExpression == RelationalExpression
EqualityExpression != RelationalExpression
EqualityExpression === RelationalExpression
EqualityExpression !== RelationalExpression
EqualityExpressionNoIn :
RelationalExpressionNoIn
EqualityExpressionNoIn == RelationalExpressionNoIn
EqualityExpressionNoIn != RelationalExpressionNoIn
EqualityExpressionNoIn === RelationalExpressionNoIn
EqualityExpressionNoIn !== RelationalExpressionNoIn
Semantics

遲我ｾ｡貍皮ｮ怜ｭ占ｩ穂ｾ｡縺ｮ邨先棡縺ｯ蟶ｸ縺ｫ Boolean 蝙九〒縺ゅｊ縲∵ｼ皮ｮ怜ｭ舌〒遉ｺ縺輔ｌ繧矩未騾｣諤ｧ縺� 2 鬆�俣縺ｧ邯ｭ謖√＆繧後※縺�ｋ縺九←縺�°繧貞渚譏�縺吶ｋ縲�

EqualityExpressionNoIn 逕滓�隕丞援縺ｯ EqualityExpression 逕滓�隕丞援縺ｨ蜷梧ｧ倥↓隧穂ｾ｡縺輔ｌ繧九′縲∝�驛ｨ縺ｮ EqualityExpression 縺ｨ RelationalExpression 縺ｮ莉｣繧上ｊ縺ｫ縲√◎繧後◇繧� EqualityExpressionNoIn 縺ｨ RelationalExpressionNoIn 縺瑚ｩ穂ｾ｡縺輔ｌ繧九€�

11.9.1 遲我ｾ｡貍皮ｮ怜ｭ� (The Equals Operator) ( == )

逕滓�隕丞援 EqualityExpression : EqualityExpression == RelationalExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. EqualityExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. RelationalExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. 豈碑ｼ� Result(4) == Result(2) 繧貞ｮ溯｡後☆繧九€� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.9.3)
  6. Result(5) 繧定ｿ斐☆縲�

11.9.2 荳咲ｭ我ｾ｡貍皮ｮ怜ｭ� (The Does-not-equals Operator) ( != )

逕滓�隕丞援 EqualityExpression : EqualityExpression != RelationalExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. EqualityExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. RelationalExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. 豈碑ｼ� Result(4) == Result(2) 繧貞ｮ溯｡後☆繧九€� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 11.9.3)
  6. Result(5) 縺� true 縺ｪ繧峨€� false 繧定ｿ斐☆縲ゅ◎縺�〒縺ｪ縺代ｌ縺ｰ縲� true 繧定ｿ斐☆縲�

11.9.3 謚ｽ雎｡逧�ｭ我ｾ｡豈碑ｼ�い繝ｫ繧ｴ繝ｪ繧ｺ繝� (The Abstract Equality Comparison Algorithm)

x 縺ｨ y 繧貞€､縺ｨ縺吶ｋ豈碑ｼ� x==y 縺ｯ縲� true 縺ｾ縺溘� false 繧堤函謌舌☆繧九€よｬ｡縺ｮ繧医≧縺ｫ豈碑ｼ��螳溯｡後＆繧後ｋ:

  1. Type(x) 縺ｨ Type(y) 縺檎焚縺ｪ繧句�ｴ蜷医�縲√せ繝�ャ繝� 14 縺ｸ縲�
  2. Type(x) 縺� Undefined 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  3. Type(x) 縺� Null 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  4. Type(x) 縺� Number 縺ｧ縺ｪ縺代ｌ縺ｰ縲√せ繝�ャ繝� 11 縺ｸ縲�
  5. x 縺� NaN 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  6. y 縺� NaN 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  7. x 縺� y 縺ｨ蜷後§謨ｰ縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  8. x 縺� +0 縺ｧ y 縺� -0 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  9. x 縺� -0 縺ｧ y 縺� +0 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  10. false 繧定ｿ斐☆縲�
  11. Type(x) 縺� String 縺ｪ繧峨�縲』 縺ｨ y 縺ｮ譁�ｭ励す繝ｼ繧ｱ繝ｳ繧ｹ縺悟ｮ悟�縺ｫ蜷後§(蜷後§髟ｷ縺輔〒蟇ｾ蠢懊☆繧倶ｽ咲ｽｮ縺ｫ蜷後§譁�ｭ励′縺ゅｋ)縺ｪ繧� true 繧定ｿ斐＠縲√◎縺�〒縺ｪ縺代ｌ縺ｰ false 繧定ｿ斐☆縲�
  12. Type(x) 縺� Boolean 縺ｪ繧峨�縲� x 縺ｨ y 縺後→繧ゅ↓ true 縺九→繧ゅ↓ false 縺ｪ繧� true 繧定ｿ斐＠縲√◎縺�〒縺ｪ縺代ｌ縺ｰ false 繧定ｿ斐☆縲�
  13. x 縺ｨ y 縺悟酔縺倥が繝悶ず繧ｧ繧ｯ繝医ｒ蜿ら�縺励※縺�ｋ縺九€√∪縺溘�莠偵＞縺ｫ邨仙粋縺励※縺�ｋ繧ｪ繝悶ず繧ｧ繧ｯ繝�(繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ13.1.2) 繧貞盾辣ｧ縺励※縺�ｌ縺ｰ true 繧定ｿ斐＠縲√◎縺�〒縺ｪ縺代ｌ縺ｰ false 繧定ｿ斐☆縲�
  14. x 縺� null 縺ｧ y 縺� undefined 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  15. x 縺� undefined 縺ｧ y 縺� null 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  16. Type(x) 縺� Number 縺ｧ Type(y) 縺� String 縺ｪ繧峨�縲∵ｯ碑ｼ� x == ToNumber(y) 縺ｮ邨先棡繧定ｿ斐☆縲�
  17. Type(x) 縺� String 縺ｧ Type(y) 縺� Number 縺ｪ繧峨�縲∵ｯ碑ｼ� ToNumber(x) == y 縺ｮ邨先棡繧定ｿ斐☆縲�
  18. Type(x) 縺� Boolean 縺ｪ繧峨�縲∵ｯ碑ｼ� ToNumber(x) == y 縺ｮ邨先棡繧定ｿ斐☆縲�
  19. Type(y) 縺� Boolean 縺ｪ繧峨�縲∵ｯ碑ｼ� x == ToNumber(y) 縺ｮ邨先棡繧定ｿ斐☆縲�
  20. Type(x) 縺� String 縺� Number 縺ｧ Type(y) 縺� Object 縺ｪ繧峨�縲∵ｯ碑ｼ� x == ToPrimitive(y) 縺ｮ邨先棡繧定ｿ斐☆縲�
  21. Type(x) 縺� Object 縺ｧ Type(y) 縺� String 縺� Number 縺ｪ繧峨�縲∵ｯ碑ｼ� ToPrimitive(x) == y 縺ｮ邨先棡繧定ｿ斐☆縲�
  22. false 繧定ｿ斐☆縲�

NOTE 遲我ｾ｡縺ｮ荳翫�螳夂ｾｩ繧剃ｸ弱∴繧峨ｌ繧�:

"" + a == "" + b 縺ｧ譁�ｭ怜�豈碑ｼ�ｒ蠑ｷ蛻ｶ縺ｧ縺阪ｋ縲�

a - 0 == b - 0 縺ｧ謨ｰ蛟､豈碑ｼ�ｒ蠑ｷ蛻ｶ縺ｧ縺阪ｋ縲�

!a == !b 縺ｧ逵溷⊃豈碑ｼ�ｒ蠑ｷ蛻ｶ縺ｧ縺阪ｋ縲�

遲我ｾ｡貍皮ｮ怜ｭ舌�谺｡縺ｮ invariants 繧堤ｶｭ謖√☆繧�:

  1. A != B 縺ｯ !(A == B) 縺ｨ遲峨＠縺�€�
  2. A == B 縺ｯ縲� A 縺ｨ B 縺ｮ隧穂ｾ｡縺ｮ鬆�ｺ上ｒ髯､縺阪€� B == A 縺ｨ遲峨＠縺�€�

遲我ｾ｡貍皮ｮ怜ｭ舌�蟶ｸ縺ｫ騾夐℃ (transitive) 縺ｧ縺ｯ縺ｪ縺�€ゆｾ九∴縺ｰ縲∝酔縺俶枚蟄怜�蛟､繧偵≠繧峨ｏ縺� 2 蛟九�蛹ｺ蛻･縺輔ｌ繧� String 繧ｪ繝悶ず繧ｧ繧ｯ繝医′蟄伜惠蜿ｯ閭ｽ縺ｧ縺ゅｋ; 縺昴ｌ縺槭ｌ縺ｮ String 繧ｪ繝悶ず繧ｧ繧ｯ繝医� == 貍皮ｮ怜ｭ舌↓繧医▲縺ｦ譁�ｭ怜�蛟､縺檎ｭ峨＠縺�→縺ｯ閠�∴繧峨ｌ繧九′縲� 2 蛟九� String 繧ｪ繝悶ず繧ｧ繧ｯ繝医�莠偵＞縺ｫ遲我ｾ｡縺ｫ縺ｯ縺ｪ繧峨↑縲�

譁�ｭ怜�豈碑ｼ��縲√さ繝ｼ繝峨�繧､繝ｳ繝亥€､縺ｮ繧ｷ繝ｼ繧ｱ繝ｳ繧ｹ縺ｮ蛟､縺ｫ蜊倡ｴ斐↑遲我ｾ｡讀懈渊繧剃ｽｿ逕ｨ縺吶ｋ縲よ枚蟄励ｄ譁�ｭ怜�縺ｮ遲我ｾ｡諤ｧ縲√♀繧医� Unicode 2.0 莉墓ｧ� 縺ｧ螳夂ｾｩ縺輔ｌ繧矩��ｺ上�辣ｧ蜷医�縲√ｈ繧願､�尅縺ｧ諢丞袖隲也噪縺ｫ謖�髄縺励◆螳夂ｾｩ繧堤畑縺�ｋ隧ｦ縺ｿ縺ｯ縺ｪ縺�€ゅ◎繧後ｆ縺医€� Unicode 讓呎ｺ悶↓繧医▲縺ｦ隕乗ｺ也噪縺ｫ遲峨＠縺�枚蟄怜�縺御ｸ咲ｭ我ｾ｡縺ｨ讀懈渊縺輔ｌ繧九°繧ゅ＠繧後↑縺�€ょ柑譫懊↓縺翫＞縺ｦ縺薙�繧｢繝ｫ繧ｴ繝ｪ繧ｺ繝�縺ｯ縲∝曙譁ｹ縺ｮ譁�ｭ怜�縺梧里縺ｫ豁｣隕丞喧蠖｢蠑上〒縺ゅｋ縺薙→繧呈Φ螳壹☆繧九€�

11.9.4 蜴ｳ蟇�ｭ我ｾ｡貍皮ｮ怜ｭ� (The Strict Equals Operator) ( === )

逕滓�隕丞援 EqualityExpression : EqualityExpression === RelationalExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. EqualityExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. RelationalExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. 豈碑ｼ� Result(4) === Result(2) 繧定｡後≧縲� (蠕瑚ｿｰ)
  6. Result(5) 繧定ｿ斐☆縲�

11.9.5 蜴ｳ蟇�ｸ咲ｭ我ｾ｡貍皮ｮ怜ｭ� (The Strict Does-not-equal Operator) ( !== )

逕滓�隕丞援 EqualityExpression : EqualityExpression !== RelationalExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. EqualityExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. RelationalExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. 豈碑ｼ� Result(4) === Result(2) 繧定｡後≧縲� (蠕瑚ｿｰ)
  6. Result(5) 縺� true 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲ゅ◎縺�〒縺ｪ縺代ｌ縺ｰ縲� true 繧定ｿ斐☆縲�

11.9.6 蜴ｳ蟇�ｭ我ｾ｡豈碑ｼ�い繝ｫ繧ｴ繝ｪ繧ｺ繝� (The Strict Equality Comparison Algorithm)

x 縺ｨ y 繧貞€､縺ｨ縺励※縲∵ｯ碑ｼ� x === y 縺ｯ true 縺ｾ縺溘� false 繧堤函謌舌☆繧九€ゅ◎縺ｮ繧医≧縺ｪ豈碑ｼ��谺｡縺ｮ繧医≧縺ｫ陦後ｏ繧後ｋ:

  1. Type(x) 縺� Type(y) 縺ｨ逡ｰ縺ｪ繧九↑繧峨�縲� false 繧定ｿ斐☆縲�
  2. Type(x) 縺� Undefined 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  3. Type(x) 縺� Null 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  4. Type(x) 縺� Number 縺ｧ縺ｪ縺�↑繧峨�縲� 繧ｹ繝�ャ繝� 11 縺ｸ縲�
  5. x 縺� NaN 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  6. y 縺� NaN 縺ｪ繧峨�縲� false 繧定ｿ斐☆縲�
  7. x 縺� y 縺ｨ蜷後§謨ｰ縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  8. x 縺� +0 縺九▽ y 縺� -0 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  9. x 縺� -0 縺九▽ y 縺� +0 縺ｪ繧峨�縲� true 繧定ｿ斐☆縲�
  10. false 繧定ｿ斐☆縲�
  11. Type(x) 縺� String 縺ｪ繧峨�縲� x 縺ｨ y 縺悟宍蟇�↓蜷後§譁�ｭ励す繝ｼ繧ｱ繝ｳ繧ｹ (蜷後§髟ｷ縺輔〒蟇ｾ蠢懊☆繧倶ｽ咲ｽｮ縺悟酔縺俶枚蟄�) 縺ｧ縺ゅｋ縺ｪ繧� true 繧定ｿ斐☆; 縺昴≧縺ｧ縺ｪ縺�↑繧峨�縲� false 繧定ｿ斐☆縲�
  12. If Type(x) 縺� Boolean 縺ｪ繧峨�縲� x 縺ｨ y 縺悟�縺ｫ true 縺ｧ縺ゅｋ縺九€∝�縺ｫ false 縺ｧ縺ゅｋ縺ｪ繧� true 繧定ｿ斐☆; 縺昴≧縺ｧ縺ｪ縺�↑繧峨�縲� false 繧定ｿ斐☆縲�
  13. x 縺ｨ y 縺悟酔縺倥が繝悶ず繧ｧ繧ｯ繝医ｒ蜿ら�縺励※縺�ｋ縺ｪ繧峨�縲√∪縺溘◎繧後ｉ縺御ｺ偵＞縺ｫ邨仙粋縺励◆繧ｪ繝悶ず繧ｧ繧ｯ繝� (繧ｻ繧ｯ繧ｷ繝ｧ繝ｳ 13.1.2) 繧貞盾辣ｧ縺励※縺�ｋ縺ｪ繧峨�縲� true 繧定ｿ斐☆縲ゅ◎縺�〒縺ｪ縺�↑繧峨�縲� false 繧定ｿ斐☆縲�

11.10 繝舌う繝翫Μ繝薙ャ繝域ｼ皮ｮ怜ｭ� (Binary Bitwise Operators)

Syntax
BitwiseANDExpression :
EqualityExpression
BitwiseANDExpression & EqualityExpression
BitwiseANDExpressionNoIn :
EqualityExpressionNoIn
BitwiseANDExpressionNoIn & EqualityExpressionNoIn
BitwiseXORExpression :
BitwiseANDExpression
BitwiseXORExpression ^ BitwiseANDExpression
BitwiseXORExpressionNoIn :
BitwiseANDExpressionNoIn
BitwiseXORExpressionNoIn ^ BitwiseANDExpressionNoIn
BitwiseORExpression :
BitwiseXORExpression
BitwiseORExpression | BitwiseXORExpression
BitwiseORExpressionNoIn :
BitwiseXORExpressionNoIn
BitwiseORExpressionNoIn | BitwiseXORExpressionNoIn
Semantics

@ 縺ｮ縺ｨ縺薙ｍ繧剃ｸ翫�逕滓�隕丞援縺ｮ繝薙ャ繝域ｼ皮ｮ怜ｭ舌→縺励※縲∫函謌占ｦ丞援 A : A @ B 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. A 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. B 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. ToInt32(Result(2)) 繧貞他蜃ｺ縺吶€�
  6. ToInt32(Result(4)) 繧貞他蜃ｺ縺吶€�
  7. 繝薙ャ繝域ｼ皮ｮ怜ｭ� @ 繧� Result(5) 縺ｨ Result(6) 縺ｫ驕ｩ逕ｨ縺吶ｋ縲らｵ先棡縺ｯ隨ｦ蜿ｷ莉� 32 繝薙ャ繝域紛謨ｰ縺ｧ縺ゅｋ縲�
  8. Result(7) 繧定ｿ斐☆縲�

11.11 繝舌う繝翫Μ隲也炊貍皮ｮ怜ｭ� (Binary Logical Operators)

Syntax
LogicalANDExpression :
BitwiseORExpression
LogicalANDExpression && BitwiseORExpression
LogicalANDExpressionNoIn :
BitwiseORExpressionNoIn
LogicalANDExpressionNoIn && BitwiseORExpressionNoIn
LogicalORExpression :
LogicalANDExpression
LogicalORExpression || LogicalANDExpression
LogicalORExpressionNoIn :
LogicalANDExpressionNoIn
LogicalORExpressionNoIn || LogicalANDExpressionNoIn
Semantics

逕滓�隕丞援 LogicalANDExpression : LogicalANDExpression && BitwiseORExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. LogicalANDExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToBoolean(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. Result(3) 縺� false 縺ｪ繧峨�縲� Result(2) 繧定ｿ斐☆縲�
  5. BitwiseORExpression 繧定ｩ穂ｾ｡縲�
  6. GetValue(Result(5)) 繧貞他蜃ｺ縺吶€�
  7. Result(6) 繧定ｿ斐☆縲�

逕滓�隕丞援 LogicalORExpression : LogicalORExpression || LogicalANDExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. LogicalORExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToBoolean(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. Result(3) 縺� true 縺ｪ繧峨�縲� Result(2) 繧定ｿ斐☆縲�
  5. LogicalANDExpression 繧定ｩ穂ｾ｡縲�
  6. GetValue(Result(5)) 繧貞他蜃ｺ縺吶€�
  7. Result(6) 繧定ｿ斐☆縲�

LogicalANDExpressionNoIn 逕滓�隕丞援縺ｨ LogicalORExpressionNoIn 逕滓�隕丞援縺ｯ縲� LogicalANDExpression 逕滓�隕丞援縺ｨ LogicalORExpression 逕滓�隕丞援縺ｨ蜷梧ｧ倥↓隧穂ｾ｡縺輔ｌ繧九′縲∝�驛ｨ縺ｮ LogicalANDExpression, BitwiseORExpression, LogicalORExpression, 縺ｮ莉｣繧上ｊ縺ｫ縲√◎繧後◇繧� LogicalANDExpressionNoIn, BitwiseORExpressionNoIn, LogicalORExpressionNoIn 縺瑚ｩ穂ｾ｡縺輔ｌ繧九€�

NOTE && 貍皮ｮ怜ｭ舌€√∪縺� || 貍皮ｮ怜ｭ舌�逕滓�縺吶ｋ蛟､縺� Boolean 蝙九〒縺ゅｋ蠢�ｦ√�縺ｪ縺�€ら函謌舌＆繧後ｋ蛟､縺ｯ蟶ｸ縺ｫ縲� 2 蛟九�鬆�ｼ上�縺�■縺ｮ 1 縺､縺ｮ蛟､縺ｧ縺ゅｋ縲�.

11.12 譚｡莉ｶ貍皮ｮ怜ｭ� (Conditional Operator) ( ?: )

Syntax
ConditionalExpression :
LogicalORExpression
LogicalORExpression ? AssignmentExpression : AssignmentExpression
ConditionalExpressionNoIn :
LogicalORExpressionNoIn
LogicalORExpressionNoIn ? AssignmentExpression : AssignmentExpressionNoIn
Semantics

逕滓�隕丞援 ConditionalExpression : LogicalORExpression ? AssignmentExpression : AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. LogicalORExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. ToBoolean(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. Result(3) 縺� false 縺ｪ繧峨�縲√せ繝�ャ繝� 8 縺ｸ縲�
  5. 譛€蛻昴� AssignmentExpression 繧定ｩ穂ｾ｡縲�
  6. GetValue(Result(5)) 繧貞他蜃ｺ縺吶€�
  7. Result(6) 繧定ｿ斐☆縲�
  8. 2 逡ｪ逶ｮ縺ｮ AssignmentExpression 繧定ｩ穂ｾ｡縲�
  9. GetValue(Result(8)) 繧貞他蜃ｺ縺吶€�
  10. Result(9) 繧定ｿ斐☆縲�

ConditionalExpressionNoIn 逕滓�隕丞援縺ｯ縲� ConditionalExpression 逕滓�隕丞援縺ｨ蜷梧ｧ倥↓隧穂ｾ｡縺輔ｌ繧九′縲∝�驛ｨ縺ｮ LogicalORExpression, 1 縺､逶ｮ縺ｮ AssignmentExpression, 2 縺､逶ｮ縺ｮ AssignmentExpression, 縺ｮ莉｣繧上ｊ縺ｫ縲√◎繧後◇繧� LogicalORExpressionNoIn, AssignmentExpression, AssignmentExpressionNoIn 縺瑚ｩ穂ｾ｡縺輔ｌ繧九€�

NOTE ECMAScript 縺ｫ縺翫￠繧� ConditionalExpression 縺ｮ譁�ｳ輔�縲� C 縺翫ｈ縺ｳ JAVA 縺ｨ縺ｯ闍･蟷ｲ逡ｰ縺ｪ繧翫€� 2 縺､逶ｮ縺ｮ驛ｨ蛻�ｼ上′ Expression 縺ｧ縺ゅｋ縺薙→繧偵◎繧後◇繧瑚ｨｱ蜿ｯ縺吶ｋ縺後€� 3 縺､逶ｮ縺ｮ蠑上′ ConditionalExpression 縺ｧ縺ゅｋ縺薙→繧貞宛髯舌☆繧九€� ECMAScript 縺ｫ縺翫￠繧九％縺ｮ蟾ｮ逡ｰ縺ｯ縲� 莉｣蜈･蠑上′縺ｩ縺｡繧峨�譚｡莉ｶ縺ｫ繧ょｷｦ蜿ｳ縺輔ｌ繧九％縺ｨ繧定ｨｱ蜿ｯ縺励€∵ｷｷ荵ｱ縺ｨ荳ｭ螟ｮ蠑上′繧ｫ繝ｳ繝槫ｼ上〒縺ゅｋ繧医≧縺ｪ縺ゅ∪繧頑э蜻ｳ縺ｮ縺ｪ縺�こ繝ｼ繧ｹ繧定€��縺励↑縺�％縺ｨ繧貞虚讖溘→縺励※縺�ｋ縲�

11.13 莉｣蜈･貍皮ｮ怜ｭ� (Assignment Operators)

Syntax
AssignmentExpression :
ConditionalExpression
LeftHandSideExpression AssignmentOperator AssignmentExpression
AssignmentExpressionNoIn :
ConditionalExpressionNoIn
LeftHandSideExpression AssignmentOperator AssignmentExpressionNoIn
AssignmentOperator : one of
= *= /= %= += -= <<= >>= >>>= &= ^= |=
Semantics

AssignmentExpressionNoIn 逕滓�隕丞援縺ｯ縲� AssignmentExpression 縺ｨ蜷梧ｧ倥↓隧穂ｾ｡縺輔ｌ繧九′縲� AssignmentExpression 縺ｫ蜷ｫ縺ｾ繧後ｋ ConditionalExpression 縺ｨ AssignmentExpression 縺ｮ莉｣繧上ｊ縺ｫ ConditionalExpressionNoIn 蜿翫� AssignmentExpressionNoIn 縺後◎繧後◇繧瑚ｩ穂ｾ｡縺輔ｌ繧九€�

11.13.1 蜊倡ｴ比ｻ｣蜈･ (Simple Assignment) ( = )

逕滓�隕丞援 AssignmentExpression : LeftHandSideExpression = AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. LeftHandSideExpression 繧定ｩ穂ｾ｡縲�
  2. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  3. GetValue(Result(2)) 繧貞他蜃ｺ縺吶€�
  4. PutValue(Result(1), Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(3) 繧定ｿ斐☆縲�

11.13.2 隍�粋莉｣蜈･ (Compound Assignment) ( op= )

@ 縺ｮ縺ｨ縺薙ｍ縺ｯ荳翫↓遉ｺ縺励◆貍皮ｮ怜ｭ舌�荳€縺､繧偵≠繧峨ｏ縺咏函謌占ｦ丞援 AssignmentExpression : LeftHandSideExpression @ = AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. LeftHandSideExpression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(2) 縺ｨ Result(4) 縺ｫ縲∵ｼ皮ｮ怜ｭ� @ 繧帝←逕ｨ縺吶ｋ縲�
  6. PutValue(Result(1), Result(5)) 繧貞他蜃ｺ縺吶€�
  7. Result(5) 繧定ｿ斐☆縲�

11.14 繧ｫ繝ｳ繝樊ｼ皮ｮ怜ｭ� (Comma Operator) ( , )

Syntax
Expression :
AssignmentExpression
Expression , AssignmentExpression
ExpressionNoIn :
AssignmentExpressionNoIn
ExpressionNoIn , AssignmentExpressionNoIn
Semantics

逕滓�隕丞援 Expression : Expression , AssignmentExpression 縺ｯ縲∵ｬ｡縺ｮ繧医≧縺ｫ隧穂ｾ｡縺輔ｌ繧�:

  1. Expression 繧定ｩ穂ｾ｡縲�
  2. GetValue(Result(1)) 繧貞他蜃ｺ縺吶€�
  3. AssignmentExpression 繧定ｩ穂ｾ｡縲�
  4. GetValue(Result(3)) 繧貞他蜃ｺ縺吶€�
  5. Result(4) 繧定ｿ斐☆縲�

ExpressionNoIn 逕滓�隕丞援縺ｯ縲� Expression 逕滓�隕丞援縺ｨ蜷梧ｧ倥↓隧穂ｾ｡縺輔ｌ繧九′縲� Expression 縺ｨ AssignmentExpression, 縺ｮ莉｣繧上ｊ縺ｫ縲√◎繧後◇繧� ExpressionNoIn 縺ｨ AssignmentExpressionNoIn 縺瑚ｩ穂ｾ｡縺輔ｌ繧九€�

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