JS 相等比较相关

[oceanpad]

请依次计算下列输出的值：

console.log( +0 ==  -0 )
console.log( +0 === -0 )
console.log( Object.is(+0, -0) )

console.log( "1" == 1 )
console.log( "1" === 1 )
console.log( Object.is("1", 1) )

console.log( new String("foo") == new String("foo") )
console.log( new String("foo") === new String("foo") )
console.log( Object.is(new String("foo") , new String("foo") ) )

console.log( new String("foo") == "foo" )
console.log( new String("foo") === "foo" )
console.log( Object.is(new String("foo") , "foo" ) )

const a = {}
const b = a 
console.log( a == b  )
console.log( a === b  )
console.log( Object.is(a, b) )

console.log( NaN == NaN )
console.log( NaN === NaN )
console.log( Object.is(NaN, NaN) )

[RookieDay]

下面是我的理解，有什么问题还望指正

• 纠正一下这道题

  console.log( “1” == 1 )     这里双引号应该切换成英文输入法的,不然运行会出错
  console.log( “1” === 1 )
  console.log( Object.is(“1”, 1) )

• 这道题我觉得可以用MDN里面这张图来解释一下 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Equality_comparisons_and_sameness

• 谢谢这道题目，原先不知道Object.is() ,偶然发现，分享一下 http://stackoverflow.com/questions/30543190/object-is-vs
• 结果如下

  true
  true
  false 
  true 
  false
  false
  false
  false
  false
  true
  false
  false
  true
  true
  true
  false
  false
  true

[oceanpad]

@RookieDay 非常感谢提醒，已经修改成英字""。

[MrZWH]

@RookieDay 你给的链接都404了(:з」∠)