简写形式与变量解构

    let web={name:"houdunern",url:"xxx.com"}
    let {name,url}=web;
    console.log(name,url);    let web={name:"houdunern",url:"xxx.com"}
    let {name,url}=web;
    console.log(name,url);

    let arr=["houdunren","xxx.com"];
    // let [,b]=arr;
    let [a,b]=arr;
    console.log(a,b)

    let name="houdunren",url="xxx.com";
    let opt={name,url};//这个写法相当于let opt={name:name,url:url};
    console.log(opt);

    let hd={
        name:"houdunren",
        lesson:{
            title:"javascript"
        }
    };

    let {
        name,
        lesson:{title}
    }=hd;
    console.log(name,title);

    let arr=["houdunren","xxx.com"];
    let [a,b,c="hdcms"]=arr;
    console.log(a,b,c);
        let arr=["houdunren","xxx.com"];
    let [a,b,c="hdcms"]=arr;
    console.log(a,b,c);
    

    let arr={a:"houdunren",b:"xxx.com",c:"123"};
    let {a,b,c="hdcms"}=arr;
    console.log(a,b,c);

  function createElement(options={}){
        let {width=200,height=100,backgroundColor='red'}=options;
        console.log(width,height,backgroundColor);
      const div=  document.createElement('div'  );
      div.style.width=width+'px';
      div.style.height=height+'px';
      div.style.backgroundColor=backgroundColor;
      document.body.appendChild(div);
    }
    createElement({width:1000,backgroundColor:'green'});