console补充

https://www.bilibili.com/medialist/play/watchlater/BV1a64y147fs

1.{}

 const a =100,b=200,c=300;
        console.log(a,b,c);
        console.log({a,b,c});

2.time

  console.time('timer')
        let count;
        for(let i = 0 ;i<100;i++){
            count = i;
        }
        console.timeEnd('timer')

注意：这两个名称要对应起来 timer

计算timer内运行的时间

如果加入console.log会浪费大量时间

   console.time('timer')
        let count;
        for(let i = 0 ;i<100;i++){
            count = i;
            console.log(i);
        }
        console.timeEnd('timer')

dir

console.dir打印对象

console.log(document);

console.dir(document),这种会有格式化，看着舒服