JavaScript中的==和===

console.log('[] == []是:'+([] == []));     //false
console.log('[] === []是:'+([] === []));  //false
console.log('{} == {}是:'+({} == {}));    //false
console.log('{} === {}是:'+({} === {}));    //false
 //true
console.log( '[] == !{}是:'+([] == !{} )); /*!{}是个布尔值,为false,因此我们比较的是 [] == 0*/
var n0 = 123;
var n1 = new Number(123);
var n2 = new Number(123);
var n3 = Number(123);
var n4 = Number(123);

console.log('n0 == n1是:'+(n0 == n1));      //true
console.log('n0 == n3是:'+(n0 == n3));        //true
console.log('n0 === n1是:'+(n0 === n1));     //false
console.log('n0 === n3是:'+(n0 === n3));     //true

console.log('n1 == n2是:'+(n1 == n2));      //false
console.log('n1 === n2是:'+(n1 === n2));      //false
console.log('n1 == n3是:'+(n1 == n3));     //true
console.log('n1 === n3是:'+(n1 === n3));     //false

console.log('n3 == n4是:'+(n3 == n4));     //true
console.log('n3 === n4是:'+(n3 === n4));     //true

输出截图:

compare_thumb.png

原文:http://www.ido321.com/1427.html

原文地址:https://www.cnblogs.com/ido321/p/4317219.html