javascript - JavaScript中==和===之间的区别[重复](Difference between == and === in JavaScript [duplicate])

Question

This question already has an answer here:

(这个问题已经在这里有了答案：)

• Which equals operator (== vs ===) should be used in JavaScript comparisons?

  (JavaScript比较中应使用哪个等于运算符（== vs ===）？)

  49 answers

  (49个答案)

What is the difference between == and === in JavaScript?

(JavaScript中==和===什么区别？)

I have also seen != and !== operators.

(我也看到过!=和!==运算符。)

Are there more such operators?

(还有更多这样的运营商吗？)

  ask by Shiva translate from so

Answer 1

Take a look here: http://longgoldenears.blogspot.com/2007/09/triple-equals-in-javascript.html

(在这里看看： http : //longgoldenears.blogspot.com/2007/09/triple-equals-in-javascript.html)

The 3 equal signs mean "equality without type coercion".

(3个等号表示“没有类型强制的平等”。)

Using the triple equals, the values must be equal in type as well.

(使用三重等于，值的类型也必须相等。)

0 == false   // true
0 === false  // false, because they are of a different type
1 == "1"     // true, automatic type conversion for value only
1 === "1"    // false, because they are of a different type
null == undefined // true
null === undefined // false
'0' == false // true
'0' === false // false