练习

var myfamily = [
             {
            relation:"dady",
            like:"唱歌",
            location:"广东"
        },{
            relation:"mom",
            like:"看剧",
            location:"江西"
        },{
            relation:"my",
            like:"timi",
            location:"湖北"
        }
        ]

for(
    var i =0;
   i<=3 ;
   i++
){
    console.log(i)
}

var str = "hello world \"good\""
console.log(str);

var a = 10;
var b = a++ + 30 + a++;
console.log(a);
console.log(b)；

var a =10 && 20;
console.log(a);
var b =10 || 0;
console.log(b);

var a = "21"+4-true+"3";
console.log(a);
var a = 10;
a++;
b= ++a +2;
c= ++b + a++ +4;
console.log(a,b,c);