【学习笔记】ES6 标准 - 对象简洁语法

/*----------对象简洁语法-----------*/

// JSON  注:尽量不要在JSON中使用箭头函数;
{
    let name = '奶牛';
    let age = 18;
    let json = {
        name,
        age,
        // showA:function(){
        //  return this.name
        // },
        showA(){
            return this.name
        }
    }
    console.log(json.showA());
}

// Object.is();用来比较两个值是否相等;
{
    console.log(NaN == NaN);  //false
    console.log(Object.is(NaN, NaN)); //true
    console.log(+0 == -0); //true
    console.log(Object.is(+0, -0));  //false
    console.log("aaa" == "aac"); //false
    console.log(Object.is("aaa", "aac"));  //false
}

// Object.assign();用来合并对象  实际用途：1.复制对象, 2.合并参数（默认参数）;
//      Object.assign({},json1,json2,json3)
{
    let json4 = [1,2,3,4];
    let json5 = Object.assign([],json4);
    json5.push(5)
    console.log(json4,json5)

    let json = {a:1};
    let json2 = {b:2,a:2};
    let json3 = {c:3};
    let obj = Object.assign({},json,json2,json3);
    console.log(obj);

    function ajax(options) {
        let defaults = {
            type:'get',
            data:'默认值'
        };
        let json = Object.assign({}, defaults, options)
        console.log(json);
    }
    let type = 'post';
    let data = '用户1';
    ajax({type, data});
}

// Object.keys();  对象key数组    循环 for(let key of arr){
{
    /*老写法*/
    /*let json = {
        a:1,
        b:2,
        c:3,
        d(){
            return 4
        }
    };

    for(let key of Object.keys(json)){
        console.log(key)
    }*/
    let {keys, assign, entries} = Object;
    let json = {
        a:1,
        b:2,
        c:3,
        d(){
            return 4
        }
    };

    for(let [key, val] of entries(json)){
        console.log(key, val)
    }
}