ES6--》对象扩展方法

<script>constobj= {
name:'张三',
age:18,
sayName(){
console.log('hello world');
        }
    }
console.log(obj.sayName.name);//sayName</script>

<script>constobj= {
getfoo(){},
setfoo(x){}
    }
constdescriptor=Object.getOwnPropertyDescriptor(obj, 'foo');
console.log(descriptor.get.name);//get foo</script>

<script>// Function构造函数创造的函数，name属性返回anonymous。console.log((newFunction()).name);//anonymous// bind方法创造的函数，name属性返回bound加上原函数的名字。vardoSomething=function(){}
console.log(doSomething.bind().name);//bound doSomething</script>

<script>constperson= {
x:'hello',
say(){
console.log(this.x);
        }
    }
constobj= {
x:'world',
say(){
super.say()
        }
    }
Object.setPrototypeOf(obj,person)//，该对象将指定对象的原型(即内部[[Prototype]]属性)设置为另一个对象或为null。console.log(obj.say());//world</script>

<script>varobj= {
name:'张三',
name1:'张三',
gender:'男',
age:18,
say(){
console.log('hello world');
        }
    }
console.log(Object.is(obj.name,obj.name1));//trueconsole.log(Object.is(1,1));//true// Object.is() 和 === 的区别在于以下特殊例子console.log(+0===-0);//trueconsole.log(Object.is(+0,-0));//falseconsole.log(NaN===NaN);//falseconsole.log(Object.is(NaN,NaN));//true</script>

<script>varobj= {
a:1,
b:2,
c:'我是c'    }
varobj1= {
a:2, //当目标对象与源对象有同名属性，或多个源对象有同名属性，则后面的属性会覆盖前面的属性d:3,
e:'我是e'    }
// console.log(Object.assign(target, source1, source2));console.log(Object.assign(obj,obj1));
</script>

<script>// 参数不是对象，则会先转换成对象console.log(typeofObject.assign(2)); //object// null和undefined无法转对象，作为目标对象为false，但是作为源对象为true的// console.log(Object.assign(null,2));//报错提醒 Cannot convert undefined or null to object// console.log(Object.assign(2,null));//没报错// 其他类型像数值、字符串、布尔值虽然不会报错，但只有字符串会以数组形式拷入目标对象，其他值不会产生效果constx='abc'consty=123constz=trueconsole.log(Object.assign({},x));//{0: 'a', 1: 'b', 2: 'c'}console.log(Object.assign({},y));//{}console.log(Object.assign({},z));//{}</script>

<script>// Object.assign()实行的是浅拷贝，如果源对象发生任何变化，都会反映到目标对象上constobj1= {a:1,b:2,c:{d:3}}
constobj2=Object.assign({},obj1)
obj1.c.d=3.14console.log(obj2.c.d);
// Object.assign()可以用来处理数组console.log(Object.assign([1,2,3],[4,5]));// [4, 5, 3]// Object.assign()可以用来对取值函数进行处理，求值之后再处理consta= {
getfoo(){
return1        }
    }
console.log(Object.assign({},a));//{foo: 1}</script>

<script>constobj= {
num:12,
getsay(){
return'hello world'        }
    }
console.log(Object.getOwnPropertyDescriptors(obj));
</script>

<script>letproto= {}
letobj= {x:10}
Object.setPrototypeOf(obj,proto)
proto.y=11proto.z=12console.log(obj.x);//10console.log(obj.y);//11console.log(obj.z);//12</script>

<script>functionfoo(){}
constf=newfoo()
console.log(Object.getPrototypeOf(f) ===foo.prototype);//trueObject.setPrototypeOf(f,Object.prototype)//修改原型对象console.log(Object.getPrototypeOf(f) ===foo.prototype);//false</script>

<script>// Object.keys() 返回所有可遍历的键名varobj= {aa:1,bb:'我是b',cc:2}
console.log(Object.keys(obj));//['aa', 'bb', 'cc']// Object.values() 返回所有可遍历的属性的键值,键值排序按属性名数值大小排序iconstobj1= {12:'a',1:'b',18:'c'}
console.log(Object.values(obj1));//['b', 'a', 'c']// Object.entries() 返回所有可遍历属性的键值对数组constobj2= {1:'a','b':2,3:'c'}
console.log(Object.entries(obj2));//[['1', 'a'],['3', 'c'],['b', 2]]// Object.fromEntries() 与 Object.entries()操作相反，将一键值对数组转为对象。console.log(Object.fromEntries([
        ['1', 'a'],
        ['3', 'c'],
        ['b', 2]
    ]));//{1: 'a', 3: 'c', b: 2}</script>

<script>constobj=Object.create({a:12});
obj.b=34// 对象obj的属性a是继承属性，属性b是原生属性。console.log(Object.hasOwn(obj,'a'));//falseconsole.log(Object.hasOwn(obj,'b'));//true</script>