记录一下JavaScript的各种函数方法

前言

记录一下JavaScript的各种自定义工具函数。


数组

对象List分组

function groupBy(array, f) { //数据根据某个字段分组
    let groups = {};
    array.forEach(function (o) {
        let group = JSON.stringify(f(o));
        groups[group] = groups[group] || [];
        groups[group].push(o);
    });
    return Object.keys(groups).map(function (group) {
        return groups[group];
    });
}

判断数组的某个字段的值是否在数组中存在

function inArray(array, field, val) {
    var inArr = false;
    array.forEach(a => {
        if (a[field] === val) {
            inArr = true;
        }        
    })
    return inArr;
}

日期时间

获取时间(时分秒)

function getDateTime(date) {// 仅获取时间
    date = new Date(date)
    let h = date.getHours();
    let m = date.getMinutes();
    let s = date.getSeconds();
    return (h + "").padStart(2, '0') + ":" + (m + "").padStart(2, '0')
}

获取日期

function getYMDNEW(params,format) {
    let newDate = new Date(params);
    return newDate.getFullYear() + format + ((newDate.getMonth() + 1) + "").padStart(2, '0') + format + (newDate.getDate() + "").padStart(2, '0')
}

获取日期时间

function formatterDate(date,format) {  // 日期时间格式化 "-"
    date = new Date(date)
    let year = date.getFullYear();
    let month = date.getMonth() + 1;
    let day = date.getDate();
    let h = date.getHours();
    let m = date.getMinutes()
    let s = date.getSeconds();
    return year + format + (month + "").padStart(2, '0') + format + (day + "").padStart(2, '0') + " " + (h + "").padStart(2, '0') + ":" + (m + "").padStart(2, '0') + ":" + (s + "").padStart(2, '0')
}

时间比较

// 判断大于
function timeGt(beginTime, nowTime) {
    let beginDate = new Date(beginTime);
    let nowDate = new Date(nowTime);
    let bTime = beginDate.getTime();
    let nTime = nowDate.getTime();
    if (nTime - bTime >= 0) {
        return true;
    } else {
        return false;
    }
}

根据一周某天获取所有日期

function getWeekDays(date) {  //获取一周所有日期
    var currentDate = new Date(date)
    var timesStamp = currentDate.getTime()
    var currenDay = currentDate.getDay()
    var dates = []
    var oneday = 24 * 60 * 60 * 1000
    for (let index = 0; index < 7; index++) {
        dates.push(getYMDNEW(new Date(timesStamp + oneday * (index - (currenDay + 6) % 7)).toLocaleDateString().replace(/\//g, '-')))
    }
    return dates
}

获取一个月的天数

/*获取一个月的天数 */
function getCountDays(date) {
    var curDate = new Date(date);
    var curYear = curDate.getFullYear()
    /* 获取当前月份 */
    var curMonth = curDate.getMonth();
    /*  生成实际的月份: 由于curMonth会比实际月份小1, 故需加1 */
    curDate.setMonth(curMonth + 1);
    /* 将日期设置为0, 这里为什么要这样设置, 我不知道原因, 这是从网上学来的 */
    curDate.setDate(0);
    /* 返回当月的天数 */
    curDate.getDate();
    var dayArry = [];
    for (var k = 1; k <= curDate.getDate(); k++) {
        var day = curYear + "-" + ((curMonth + 1) + "").padStart(2, '0')
        day += ("-" + (k + "").padStart(2, '0'))
        dayArry.push(day);
    }
    return dayArry;
}

获取一个月的第一天和最后一天

function getFirstDay(date) { //获取一个月的第一天和最后一天
    let dayArry = getCountDays(date)
    let firstEnd = []
    // console.log(dayArry)
    firstEnd.push(dayArry[0])
    firstEnd.push(dayArry[dayArry.length - 1])
    return firstEnd;
}

获取星期几

function getWeek(date) { // 获取星期
    var newDate = new Date(date);
    var day = newDate.getDay() == 0 ? 7 : newDate.getDay()
    var chnNumChar = ["一", "二", "三", "四", "五", "六", "日"];
    return "星期" + chnNumChar[day - 1]
}

获取明天日期

function getTomorrow(todayDate) {  //获取明天的日期
    todayDate = new Date(todayDate);
    var date = new Date(todayDate.getTime() + 24 * 60 * 60 * 1000);
    let year = date.getFullYear();
    let month = date.getMonth() + 1;
    let day = date.getDate();
    let h = date.getHours();
    let m = date.getMinutes()
    let s = date.getSeconds();
    return year + '-' + month + "-" + (day + "").padStart(2, '0') + " " + (h + "").padStart(2, '0') + ":" + (m + "").padStart(2, '0') + ":" + (s + "").padStart(2, '0')
}

获取昨天的日期

function getYesterday(todayDate) {  
    todayDate = new Date(todayDate);
    var date = new Date(todayDate.getTime() - 24 * 60 * 60 * 1000);
    let year = date.getFullYear();
    let month = date.getMonth() + 1;
    let day = date.getDate();
    let h = date.getHours();
    let m = date.getMinutes()
    let s = date.getSeconds();
    return year + '-' + month + "-" + (day + "").padStart(2, '0') + " " + (h + "").padStart(2, '0') + ":" + (m + "").padStart(2, '0') + ":" + (s + "").padStart(2, '0')
}

判断在时间范围内(不等于)

function timeRange(beginTime, endTime, nowTime) { //判断在时间范围内
    let beginDate = new Date(beginTime);
    let endDate = new Date(endTime);
    let nowDate = new Date(nowTime);
    let bTime = beginDate.getTime();
    let eTime = endDate.getTime();
    let nTime = nowDate.getTime();
    return (nTime - eTime < 0 && nTime - bTime > 0) ? true : false
}

判断在时间范围内(包含等于)

function timeRange2(beginTime, endTime, nowTime) { //判断在时间范围内(包括等于)
    let beginDate = new Date(beginTime);
    let endDate = new Date(endTime);
    let nowDate = new Date(nowTime);
    let bTime = beginDate.getTime();
    let eTime = endDate.getTime();
    let nTime = nowDate.getTime();
    return (nTime - eTime <= 0 && nTime - bTime >= 0) ? true : false
}

判断字段是否为日期

function isValidDate(date) {
    return date instanceof Date && !isNaN(date.getTime())
}

判断是否为空

判断数字是否为空或0

function judgeVal(val) {
    return val == '0' || val == 0 || val == null || val ==''
}

判断是否为空

function isNullOrEmpty(str) {
    return str === "" || str === null;
}