call与apply

let lisi={
    name:"李四"
};

let wangwu={
    name:"王五"
};
function User(web,url){
    console.log(web+url+this.name);
}

//都是立即执行的
User.call(lisi,"hdr","hdr.com");
User.apply(wangwu,["hdr","hdr.com"]);//用的是数组

<button>houdunren</button>

<button>hscms</button>

function show(){
    alert(this.innerHTML);
}
let btn=document.querySelectorAll("button");
for(let i=0;i<btn.length;i++){
    btn[i].addEventListener("click",event=>{
        // show.apply(event.target);//event.target指向当前的按钮对象
        show.call(event.target);//event.target指向当前的按钮对象
    });
}

    let arr=[1,2,3,4,5];

    console.log(Math.max(...arr));

    console.log(Math.max.apply(Math,arr));

function Request(){
    this.get=function(params){
        let str=Object.keys(params).map(k=>`${k}=${params[k]}`).join("&");
        let url=`https://baidu.com>${this.url}/${str}`;
        // console.log(url+"<hr>");
        document.write(url+"<hr>")
    }
}
function Article(){
    this.url="article/lists";
    Request.call(this);//call，此处没有传入参数
}
let artile=new Article();
artile.get({id:1,cat:"js"});

function User(){
    this.url="user/lists";
    Request.call(this);//call，此处没有传入参数
}

let user=new User();
user.get({id:2,role:"admin"});

let user1=new User();
user1.get({id:2,role:"admin"});