js四舍五入取0和5的整数

1、中级

  const fn = (num) => num % 5 === 0 ? num : num - num % 5;

2、高级

   const fn1 = (num) =>parseInt(num / 5) * 5;

3、骨灰级

  const fn = (num) =>~~(num / 5) * 5；

4、垃圾

  const MAXarr = String(parseInt(Number(data.numMAX) - 5)).split('');
  if (MAXarr[MAXarr.length - 1] > '0' && MAXarr[MAXarr.length - 1] < '5') {
        MAXarr[MAXarr.length - 1] = '0'
  }else if(MAXarr[MAXarr.length - 1] > '5' && MAXarr[MAXarr.length - 1] < '9'){
        MAXarr[MAXarr.length - 1] = '5'
  }