使用方式

输出:

formatTime方法:

function formatTime(countTime = 0, timeStr = "hh:mm:ss") {
  let timeSet = {
    "h": function (count) {
      return parseInt(count / 3600);
    },
    "m": function (count) {
      return parseInt(count % 3600 / 60);
    },
    "s": function (count) {
      return parseInt(count % 60);
    }
  };
  let start = 0;
  let queryCharacter = '';
  for (let i = 0; i < timeStr.length + 1; i++) {
    let character = timeStr[i]; //当前字符
    if (character !== queryCharacter) { //当前字符不等于查询字符
      if (queryCharacter) { //替换查询字符为时间
        let end = i;
        let resultStr = String(timeSet[queryCharacter](countTime));
        while (resultStr.length < end - start) {
          resultStr = '0' + resultStr;
        }
        timeStr = timeStr.slice(0, start) + resultStr + timeStr.slice(end);
        i = start + resultStr.length;
        queryCharacter = '';
      }
      if (character && timeSet[character]) { //更新查询字符和开始角标
        queryCharacter = character;
        start = i;
      }
    }
  }
  return timeStr;
}

代码片段:https://developers.weixin.qq.com/s/Dnfj4Vm97Cls

产品要求低于一小时只显示分和秒，低于一分钟只显示秒，

所有又对这个函数做了一下调整，如果需要最高位为0不显示需要多传入一个参数,

输入:

输出:

代码片段:https://developers.weixin.qq.com/s/wEteGYml7bll

formatTime方法

function formatTime(countTime = 0, timeStr = "hh:mm:ss", removeFirst = false) {
  let timeSet = {
    "h": function (count) {
      return parseInt(count / 3600);
    },
    "m": function (count) {
      return parseInt(count % 3600 / 60);
    },
    "s": function (count) {
      return parseInt(count % 60);
    }
  };
  let start = 0;
  let queryCharacter = '';
  for (let i = 0; i < timeStr.length + 1; i++) {
    let character = timeStr[i]; //当前字符
    if (character !== queryCharacter) { //当前字符不等于查询字符
      if (queryCharacter) { //替换查询字符为时间
        let end = i;
        let result = timeSet[queryCharacter](countTime);
        let resultStr = '';
        if (!removeFirst || result > 0 || start !== 0) {
          resultStr = String(result);
          while (resultStr.length < end - start) {
            resultStr = '0' + resultStr;
          }
        }
        timeStr = timeStr.slice(0, start) + resultStr + timeStr.slice(end);
        i = start + resultStr.length;
        queryCharacter = '';
      }
      if (character && timeSet[character]) { //更新查询字符和开始角标
        queryCharacter = character;
        start = i;
      } else {
        if (removeFirst && i === 0) {
          timeStr = timeStr.slice(1);
          i = -1;
        }
      }
    }
  }
  return timeStr;
}