js格式化金额数据格式化算法 避免js精度问题，保留两位小数，保持精度（小数点后两位四舍五入）

js格式化金额字段算法 避免js精度问题，保留两位小数，保持精度（小数点后两位四舍五入）

/**
 * 格式化金额字段算法 保持精度 需后端返回的均为字符串金额数据
 * @param {String} num 传入金额
 * @returns 
 */
export function thousandMark(num) {
  let d = '' + num
  d = d.split('.')
  if (d.length == 1) {
    d.push('00')
  }else if (d.length == 2) {
    if (d[1].length > 2) {
      if (d[1][2] >= 5) {
        d[1] = String(Number(d[1].slice(0, 2)) + 1)
        console.log(d[0], d[1], '[0]')
        if (d[1].length > 2) {
          d[0] = String(Number(d[0]) + Number(d[1][0]))
          console.log(d[0],d[1],'[1]')

          d[1] = d[1].slice(1, 3)
        }
      }
      d[1] = d[1].slice(0, 2)
    } else if (d[1].length == 1) {
      d[1] = d[1] + '0'
    } else if (!d[1] || d[1].length == 0) {
      d[1] = '00'
    }
  } else {
    d[0] = '0'
    d[1] = '00'
  }
  d[0] = d[0].replace(/\B(?=(?:\d{3})+$)/g, ',')
  d = d[0] + '.' + d[1]
  return d;
}

实例

console.log(thousandMark('1324323112432421.094555'))
// 1,324,323,112,432,421.09
console.log(thousandMark('1324323112432421.095'))
// 1,324,323,112,432,421.10
console.log(thousandMark('1324323112432421.095'))
// 1,324,323,112,432,421.10
console.log(thousandMark('1324323112432421.995'))
// 1,324,323,112,432,422.00