es6基础(2)--解构赋值

//解构赋值

{
    let a,b,rest;
    [a,b]=[1,2];
    console.log(a,b);
}
//数组解构赋值
{
    let a,b,rest;
    [a,b,...rest]=[1,2,3,4,5,6];
    console.log(a,b,rest);
}
//对象解构赋值
{
    let a,b;
    ({a,b}={a:1,b:2})
    console.log(a,b);
}

{
    let a,b,c,rest;
    [a,b,c=3]=[1,2];
    console.log(a,b,c);
}
//变量交换
{
    let a=1;
    let b=2;
    [a,b]=[b,a];
    console.log(a,b);
}

{
    function f(){
        return [1,2]
    }
    let a,b;
    [a,b]=f();
    console.log(a,b)
}
{
    function f(){
        return [1,2,3,4,5,6];
    }
    let a,b,c;
    [a,,,b]=f();
    console.log(a,b);
}
//当只要数组内的某几个的时候
{
    function f(){
        return [1,2,3,4,5,6];
    }
    let a,b,c;
    [a,...b]=f();
    console.log(a,b);
}
//对象的赋值
{
    let o={p:42,q:true};
    let {p,q}=o;
    console.log(p,q);
}
{
    let {a=10,b=5}={a:3};
    console.log(a,b);
}
{
    let metaData={
        title:'abc',
        test:[{
            title:'test',
            desc:'description'
        }]
    }
    let {title:esTitle,test:[{title:cntitle}]}=metaData;
    console.log(esTitle,cntitle);
}