合并对象

var obj = {a: 1}
var tar = {}
console.log(Object.assign(tar, obj))
console.log(tar === obj)

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var obj = {
  firstName: 'Yang'
}

var obj2 = {
  lastName: 'Lance'
}

var copy = Object.assign(obj, obj2);

console.log(copy === obj)

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const tar = {a: 1};
const tar1 = {b: 2, c: 2};
const tar2 = {c: 3};
Object.assign(tar, tar1, tar2);
console.log(tar);

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🌈 使用包装类

var test = Object.assign(undefined, {a: 1})
var test = Object.assign(null, {a: 1})

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var test1 = Object.assign(1, {a: 1})
var test2 = Object.assign(true, {a: 1})
var test3 = Object.assign('aa', {a: 1})
console.log(test1)
console.log(test2)
console.log(test3)

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🌈 第二个参数，在转换为对象的时候，参数的可枚举性需要为真

var test1 = Object.assign({a: 1}, undefined);
var test2 = Object.assign({a: 1}, 1);
var test3 = Object.assign({a: 1}, '123');
var test4 = Object.assign({a: 1}, true);
console.log(test1);
console.log(test2);
console.log(test3);
console.log(test4);

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var test1 = 'abc';
var test2 = true;
var test3 = 10;
console.log(new Object(test1)) // 转为类数组，可以枚举
console.log(new Object(test2))
console.log(new Object(test3))

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🌈 assign 继承属性和不可枚举属性不能够拷贝

var obj = Object.create({foo: 1}, {
	bar: {
  	value: 2
  },
  baz: {
  	value: 3,
    enumerable: true
  }
})
console.log(obj)
console.log(Object.assign({}, obj))

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