web前端常用的js封装，收藏起来备用！

做前端开发的同学是不是经常封装一些常用的函数方法，比如，日期格式、对象转换等。话不多说，直接总结一些常用的封装函数直接放在utils中拿来即用！

//数组对象深拷贝
const deepCopy = function (source) {
 return  JSON.parse(JSON.stringify(source))

}

//日期格式转换
filterTime(time) {
  const date = new Date(time)
  const Y = date.getFullYear()   // 年
  const M = date.getMonth() + 1 < 10 ? '0'+(date.getMonth()+1) : date.getMonth()+1;   //月
  const D = date.getDate() < 10 ? '0'+(date.getDate()) : date.getDate()   //日
  const HH = date.getHours() < 10 ? '0'+(date.getHours()) : date.getHours()   //时
  const MM = date.getMinutes() < 10 ? '0'+(date.getMinutes()) : date.getMinutes()   //分
  return `${Y}-${M}-${D} ${HH}:${MM}`
},

//日期转为 刚刚 几分钟 ...
 
  function timeago(dateTimeStamp){  
        var minute = 1000 * 60;      //把分，时，天，周，半个月，一个月用毫秒表示
        var hour = minute * 60;
        var day = hour * 24;
        var week = day * 7;
        var halfamonth = day * 15;
        var month = day * 30;
        var now = new Date().getTime();   //获取当前时间毫秒
        console.log(now)
        var diffValue = now - dateTimeStamp;//时间差
    
        if(diffValue < 0){
            return;
        }
        var minC = diffValue/minute;  //计算时间差的分，时，天，周，月
        var hourC = diffValue/hour;
        var dayC = diffValue/day;
        var weekC = diffValue/week;
        var monthC = diffValue/month;
        if(monthC >= 1 && monthC <= 3){
            result = " " + parseInt(monthC) + "月前"
        }else if(weekC >= 1 && weekC <= 3){
            result = " " + parseInt(weekC) + "周前"
        }else if(dayC >= 1 && dayC <= 6){
            result = " " + parseInt(dayC) + "天前"
        }else if(hourC >= 1 && hourC <= 23){
            result = " " + parseInt(hourC) + "小时前"
        }else if(minC >= 1 && minC <= 59){
            result =" " + parseInt(minC) + "分钟前"
        }else if(diffValue >= 0 && diffValue <= minute){
            result = "刚刚"
        }else {
            var datetime = new Date();
            datetime.setTime(dateTimeStamp);
            var Nyear = datetime.getFullYear();
            var Nmonth = datetime.getMonth() + 1 < 10 ? "0" + (datetime.getMonth() + 1) : datetime.getMonth() + 1;
            var Ndate = datetime.getDate() < 10 ? "0" + datetime.getDate() : datetime.getDate();
            var Nhour = datetime.getHours() < 10 ? "0" + datetime.getHours() : datetime.getHours();
            var Nminute = datetime.getMinutes() < 10 ? "0" + datetime.getMinutes() : datetime.getMinutes();
            var Nsecond = datetime.getSeconds() < 10 ? "0" + datetime.getSeconds() : datetime.getSeconds();
            result = Nyear + "-" + Nmonth + "-" + Ndate
        }
        return result;
    }

//原数据
dataOld: [{ id: '33', name: '小明', sex: "男"}, { id: '44', name: '小红', sex: "女"}] 
//接口需要的数据
dataNew: [{ value: '33', label: '小明', sex: "男"}, { value: '44', label: '小红', sex: "女"}]

//方法
function TurnToMy(dataOld){
let dataNew = [];    //新数组
dataOld.map(item => {
    let obj = {
        value: item.id,
        label: item.name,
    }
     dataNew.push(obj);
});
return dataNew 
}