1. Object.is( ); //用来判断，不同等 == 与===接近。NaN作出的调整
let obj={a:1,b:2};
Object.is(obj,obj);//true
Object.is(obj,{obj});//false
Object.is({},{});//false
Object.is('1',1);//false
Object.is(-0,0);//false
Object.is(NaN,NaN);//true
Object.is(NaN,-NaN);//true
2. Object.assign()
let obj={a:1,b:2};
Object.assign(obj,{c:3});//obj={a:1,b:2,c:3}
let obj1={a:1,b:2};
let obj2={a:'a',c:3};
Object.assign(obj1,obj2);//obj1={a:'a',b:2,c:3}
let obj1={a:1,b:2};
let obj2={a:'a',c:3};
Object.assign({},obj1,obj2);//返回新对象{a:'a',b:2,c:3}
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let arr=[1,2,3];
Object.assign(arr,['a']);//arr=['a',2,3]
let arr1=[1,2,3];
let arr2=[,,,'a','b','c']
Object.assign([],arr1,arr2);//返回新数组[1, 2, 3, "a", "b"]