日常好用的js方法

• js数字转化为千分位

1. toLocaleString方法

   const num=12345.6789

   num.toLocaleString();  // "12,345.679"`

2. 正则匹配

    function format (num) {
     return  (num+ '').replace(/(\d{1,3})(?=(\d{3})+(?:$|.))/g,'$1,')
    }

将秒转化为时分秒

    function formatSeconds(value) {
        let result = parseInt(value)
        let h = Math.floor(result / 3600) < 10 ? '0' + Math.floor(result / 3600) : Math.floor(result / 3600);
        let m = Math.floor((result / 60 % 60)) < 10 ? '0' + Math.floor((result / 60 % 60)) : Math.floor((result / 60 % 60));
        let s = Math.floor((result % 60)) < 10 ? '0' + Math.floor((result % 60)) : Math.floor((result % 60));

        let res = '';
        if(h !== '00') res += `${h}h`;
        if(m !== '00') res += `${m}min`;
        res += `${s}s`;
        return {h,m,s};
      }

多层级对象合并

function assiginObj(target = {}, sources = {}) {
  const obj = target
  if (typeof target !== 'object' || typeof sources !== 'object') {
    return sources // 如果其中一个不是对象 就返回sources
  }
  for (const key in sources) {
    // 如果target也存在 那就再次合并
    if (target.hasOwnProperty(key)) {
      obj[key] = assiginObj(target[key], sources[key])
    } else {
      // 不存在就直接添加
      obj[key] = sources[key]
    }
  }
  return obj
}

本周起始日期

function getWeekDate() {

     const now = new Date() // 当前日期

     const nowDayOfWeek = now.getDay() // 今天本周的第几天

     const nowDay = now.getDate() // 当前日

     const nowMonth = now.getMonth() // 当前月

     const nowYear = now.getFullYear() // 当前年



     const weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek)

     const weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek))

     const startTime = formatDate(weekStartDate) + ' 00:00:00'

     const endTime = formatDate(weekEndDate) + ' 23:59:59'

     return { startTime, endTime }

}