javascript怎么判断变量是否相等

[1,3,5,[2,4,6]].toString();//"1,3,5,2,4,6"

[1,null,undefined,'',2].toString();//"1,,,,2"

[{xx:2},window,1,2].toString();//"[object Object],[object Window],1,2"

Object.is(1,1);//true

Object.is('str','str');//true

Object.is({},{});//false

+0 === -0 //true

NaN === NaN //false

Object.is(+0, -0) //false

Object.is(NaN, NaN) //true

if (!Object.is) {

  Object.is = function(x, y) {

    if (x === y) {

      // 针对+0 不等于 -0的情况

      return x !== 0 || 1 / x === 1 / y;

    } else {

     // 针对NaN的情况

      return x !== x && y !== y;

    }

  };

}

let obj = {name: 'lin', age: 24};

let obj2 = {name: 'lin', age: 24};

obj === obj2;//false

JSON.stringify(obj) === JSON.stringify(obj2);//true