2020/6.30

1.'2020-06-29 23:59:59'--> '6.29'

let res='2020-06-29 23:59:59' //6.29
let res1=res .slice(5).split(" ")[0].replace("-", ".")
console.log(res1);

 2.  915998847=> 915,998,847

const totalServiceTimes=915998847

3.字符串数字

const str = '10'
const res = str * 1 //字符串数字转数字

const num=20
const res1=''+num //数字转为字符串数字

 4.js获取走动时间

created() {
   this.timer = setInterval(this.getTime1, 1000);

  },

methods: {
            getTime1() {
                const time = new Date();

                let year = time.getFullYear(); //获取年份

                let month = this.padZero(time.getMonth() + 1); //获取月份

                let day = this.padZero(time.getDate()); //获取日期

                let hour = this.padZero((time.getHours())); //获取时

                let minute = this.padZero(time.getMinutes()); //获取分

                let second = this.padZero(time.getSeconds()); //获取秒

                this.currentTime = `${year}-${month}-${day} ${hour}:${minute}:${second}`
            },
            padZero(num) {
                return ('' + num).padStart(2,'0')
            },
}

5. 9->009->[0 ,0 ,9] ; 41->041->[0 ,4 ,1]

function PrefixInteger(num, n) {
  let number = num ? (Array(n).join(0) + num).slice(-n) : 0;
  let numArr = String(number)
    .split("")
    .map(it => it * 1);
  return numArr;
}
console.log(PrefixInteger(9,3))

 function PrefixInteger(num,n=3){
    return (num+'').padStart(3,'0').split('').map(Number)


  }