关于JavaScript常用的工具函数汇总
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2024-01-10 14:58:46
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前言
随着开发经验的积累，很多人会有自己的常用站点，一些网址收藏，自己造的*或者别人的*，工具函数库等等。
这里提供一些常用的工具函数，如果你也有一些觉得挺不错的库，欢迎在下方评论????。
格式化时间戳
export function formatDateTimeStamp(date, fmt) {
// 格式化时间戳 : formatDateTimeStamp(new Date(time),'yyyy-MM-dd hh:mm:ss')
if (/(y+)/.test(fmt)) {
fmt = fmt.replace(RegExp.$1, (date.getFullYear() + '').substr(4 - RegExp.$1.length))
}
let o = {
'M+': date.getMonth() + 1,
'd+': date.getDate(),
'h+': date.getHours(),
'm+': date.getMinutes(),
's+': date.getSeconds()
}
for (let k in o) {
if (new RegExp(`(${k})`).test(fmt)) {
let str = o[k] + ''
fmt = fmt.replace(
RegExp.$1, (RegExp.$1.length === 1) ?
str :
padLeftZero(str))
}
}
return fmt
}
function padLeftZero(str) {
return ('00' + str).substr(str.length);
}
export function parseTime(time, cFormat) {
if (arguments.length === 0) {
return null
}
const format = cFormat || '{y}-{m}-{d} {h}:{i}:{s}'
let date
if (typeof time === 'object') {
date = time
} else {
if ((typeof time === 'string') && (/^[0-9]+$/.test(time))) {
time = parseInt(time)
}
if ((typeof time === 'number') && (time.toString().length === 10)) {
time = time * 1000
}
date = new Date(time)
}
const formatObj = {
y: date.getFullYear(),
m: date.getMonth() + 1,
d: date.getDate(),
h: date.getHours(),
i: date.getMinutes(),
s: date.getSeconds(),
a: date.getDay()
}
const time_str = format.replace(/{([ymdhisa])+}/g, (result, key) => {
const value = formatObj[key]
// Note: getDay() returns 0 on Sunday
if (key === 'a') {
return ['日', '一', '二', '三', '四', '五', '六'][value]
}
return value.toString().padStart(2, '0')
})
return time_str
}
// for example
// formatDateTimeStamp(new Date(1632744272 * 1000),'yyyy-MM-dd hh:mm:ss')
// parseTime(1632744272)
// 输出 ---> 2021-09-27 20:04:32
时间格式化 几分钟前 几小时前
/**
* @param {number} time
* @param {string} option
* @returns {string}
*/
export function formatTime(time, option) {
if (('' + time).length === 10) {
time = parseInt(time) * 1000
} else {
time = +time
}
const d = new Date(time)
const now = Date.now()
const diff = (now - d) / 1000
if (diff < 30) {
return '刚刚'
} else if (diff < 3600) {
// less 1 hour
return Math.ceil(diff / 60) + '分钟前'
} else if (diff < 3600 * 24) {
return Math.ceil(diff / 3600) + '小时前'
} else if (diff < 3600 * 24 * 2) {
return '1天前'
}
if (option) {
return parseTime(time, option)
} else {
return (
d.getMonth() +
1 +
'月' +
d.getDate() +
'日' +
d.getHours() +
'时' +
d.getMinutes() +
'分'
)
}
}
// for example
// formatTime(1632600000)
// 测试时间 ---> 2021-09-27 20:25:30
// 输出 ---> 一天前
/**
* Show plural label if time is plural number
* @param {number} time
* @param {string} label
* @return {string}
*/
function pluralize(time, label) {
if (time === 1) {
return time + label + ' ago'
}
return time + label + 's' + ' ago'
}
/**
* @param {number} time
*/
export function timeAgo(time) {
const between = Date.now() / 1000 - Number(time)
if (between < 3600) {
return pluralize(~~(between / 60), ' minute')
} else if (between < 86400) {
return pluralize(~~(between / 3600), ' hour')
} else {
return pluralize(~~(between / 86400), ' day')
}
}
// for example
// timeAgo(1632200000)
// 测试时间 ---> 2021-09-27 20:45:46
// 输出 ---> 6 days ago
url参数转为对象
/**
* @param {string} url
* @returns {Object}
*/
export function getQueryObject(url) {
url = url == null ? window.location.href : url
const search = url.substring(url.lastIndexOf('?') + 1)
const obj = {}
const reg = /([^?&=]+)=([^?&=]*)/g
search.replace(reg, (rs, $1, $2) => {
const name = decodeURIComponent($1)
let val = decodeURIComponent($2)
val = String(val)
obj[name] = val
return rs
})
return obj
}
// or
/**
* @param {string} url
* @returns {Object}
*/
export function param2Obj(url) {
const search = url.split('?')[1]
if (!search) {
return {}
}
return JSON.parse(
'{"' +
decodeURIComponent(search)
.replace(/"/g, '\\"')
.replace(/&/g, '","')
.replace(/=/g, '":"')
.replace(/\+/g, ' ') +
'"}'
)
}
// for example
// getQueryObject('http://xxxxxx/index?id=123')
// param2Obj('http://xxxxxx/index?id=123')
// 输出 ---> {id: "123"}
对象序列化【对象转url参数】
/**
* @param {Array} actual
* @returns {Array}
*/
function cleanArray(actual) {
const newArray = []
for (let i = 0; i < actual.length; i++) {
if (actual[i]) {
newArray.push(actual[i])
}
}
return newArray
}
/**
* @param {Object} obj
* @returns {Array}
*/
export function param(obj) {
if (!obj) return ''
return cleanArray(
Object.keys(obj).map(key => {
if (obj[key] === undefined) return ''
return encodeURIComponent(key) + '=' + encodeURIComponent(obj[key])
})
).join('&')
}
// or
export function stringfyQueryStr(obj) {
if (!obj) return '';
let pairs = [];
for (let key in obj) {
let value = obj[key];
if (value instanceof Array) {
for (let i = 0; i < value.length; ++i) {
pairs.push(encodeURIComponent(key + '[' + i + ']') + '=' + encodeURIComponent(value[i]));
}
continue;
}
pairs.push(encodeURIComponent(key) + '=' + encodeURIComponent(obj[key]));
}
return pairs.join('&');
}
// for example
param({name:'1111',sex:'wwww'})
stringfyQueryStr({name:'1111',sex:'wwww'})
// ---> 输出 name=1111&sex=wwww
本地存储
export const store = { // 本地存储
set: function(name, value, day) { // 设置
let d = new Date()
let time = 0
day = (typeof(day) === 'undefined' || !day) ? 1 : day // 时间,默认存储1天
time = d.setHours(d.getHours() + (24 * day)) // 毫秒
localStorage.setItem(name, JSON.stringify({
data: value,
time: time
}))
},
get: function(name) { // 获取
let data = localStorage.getItem(name)
if (!data) {
return null
}
let obj = JSON.parse(data)
if (new Date().getTime() > obj.time) { // 过期
localStorage.removeItem(name)
return null
} else {
return obj.data
}
},
clear: function(name) { // 清空
if (name) { // 删除键为name的缓存
localStorage.removeItem(name)
} else { // 清空全部
localStorage.clear()
}
}
}
cookie操作
export const cookie = { // cookie操作【set，get，del】
set: function(name, value, day) {
let oDate = new Date()
oDate.setDate(oDate.getDate() + (day || 30))
document.cookie = name + '=' + value + ';expires=' + oDate + "; path=/;"
},
get: function(name) {
let str = document.cookie
let arr = str.split('; ')
for (let i = 0; i < arr.length; i++) {
let newArr = arr[i].split('=')
if (newArr[0] === name) {
return newArr[1]
}
}
},
del: function(name) {
this.set(name, '', -1)
}
}
数字格式化单位
/**
* Number formatting
* like 10000 => 10k
* @param {number} num
* @param {number} digits
*/
export function numberFormatter(num, digits) {
const si = [{
value: 1E18,
symbol: 'E'
},
{
value: 1E15,
symbol: 'P'
},
{
value: 1E12,
symbol: 'T'
},
{
value: 1E9,
symbol: 'G'
},
{
value: 1E6,
symbol: 'M'
},
{
value: 1E3,
symbol: 'k'
}
]
for (let i = 0; i < si.length; i++) {
if (num >= si[i].value) {
return (num / si[i].value).toFixed(digits).replace(/\.0+$|(\.[0-9]*[1-9])0+$/, '$1') + si[i].symbol
}
}
return num.toString()
}
数字千位过滤
/**
* 10000 => "10,000"
* @param {number} num
*/
export function toThousandFilter(num) {
let targetNum = (num || 0).toString()
if (targetNum.includes('.')) {
let arr = num.split('.')
return arr[0].replace(/^-?\d+/g, m => m.replace(/(?=(?!\b)(\d{3})+$)/g, ',')) + '.' + arr[1]
} else {
return targetNum.replace(/^-?\d+/g, m => m.replace(/(?=(?!\b)(\d{3})+$)/g, ','))
}
}
过滤成版本号
/**
* version filter
* 50397188 => 3.1.0.4
* @param {number} versions
*/
export function versionFilter(versions) {
let v0 = (versions & 0xff000000) >> 24
let v1 = (versions & 0xff0000) >> 16
let v2 = (versions & 0xff00) >> 8
let v3 = versions & 0xff
return `${v0}.${v1}.${v2}.${v3}`
}
首字母大写
/**
* Upper case first char
* @param {String} string
*/
export function uppercaseFirst(string) {
return string.charAt(0).toUpperCase() + string.slice(1)
}
class骚操作
/**
* Check if an element has a class
* @param {HTMLElement} elm
* @param {string} cls
* @returns {boolean}
*/
export function hasClass(ele, cls) {
return !!ele.className.match(new RegExp('(\\s|^)' + cls + '(\\s|$)'))
}
/**
* Add class to element
* @param {HTMLElement} elm
* @param {string} cls
*/
export function addClass(ele, cls) {
if (!hasClass(ele, cls)) ele.className += ' ' + cls
}
/**
* Remove class from element
* @param {HTMLElement} elm
* @param {string} cls
*/
export function removeClass(ele, cls) {
if (hasClass(ele, cls)) {
const reg = new RegExp('(\\s|^)' + cls + '(\\s|$)')
ele.className = ele.className.replace(reg, ' ')
}
}
文本复制功能
const copyTxt = function(text, fn) { // 复制功能
if (typeof document.execCommand !== 'function') {
console.log('复制失败，请长按复制')
return
}
var dom = document.createElement('textarea')
dom.value = text
dom.setAttribute('style', 'display: block;width: 1px;height: 1px;')
document.body.appendChild(dom)
dom.select()
var result = document.execCommand('copy')
document.body.removeChild(dom)
if (result) {
console.log('复制成功')
typeof fn === 'function' && fn()
return
}
if (typeof document.createRange !== 'function') {
console.log('复制失败，请长按复制')
return
}
var range = document.createRange()
var div = document.createElement('div')
div.innerhtml = text
div.setAttribute('style', 'height: 1px;fontSize: 1px;overflow: hidden;')
document.body.appendChild(div)
range.selectNode(div)
var selection = window.getSelection()
console.log(selection)
if (selection.rangeCount > 0) {
selection.removeAllRanges()
}
selection.addRange(range)
document.execCommand('copy')
typeof fn === 'function' && fn()
console.log('复制成功')
}
判断是否是一个数组
export const castArray = value => (Array.isArray(value) ? value : [value])
// Or
export const castArray = arr=> Object.prototype.toString.call(arr) === '[object Array]'
判断是否是一个空数组
export const isEmpty = (arr) => !Array.isArray(arr) || arr.length === 0
// for example
// isEmpty([]); // true
// isEmpty([1, 2, 3]); // false
克隆一个数组
/**
* @param {Array} arr
*/
const clone = (arr) => arr.slice(0);
// Or
const clone = (arr) => [...arr];
// Or
const clone = (arr) => Array.from(arr);
// Or
const clone = (arr) => arr.map((x) => x);
// Or
const clone = (arr) => JSON.parse(JSON.stringify(arr));
// Or
const clone = (arr) => arr.concat([]);
数组去重
/**
* @param {Array} arr
* @returns {Array}
*/
export const uniqueArray = (arr) => Array.from(new Set(arr))
// Or
export const uniqueArray = (arr) => arr.filter((el, i, array) => array.indexOf(el) === i)
// Or
export const uniqueArray = (arr) => arr.reduce((acc, el) => (acc.includes(el) ? acc : [...acc, el]), [])
是否为PC端
export const isPC = function() { // 是否为PC端
let userAgentInfo = navigator.userAgent
let Agents = ['Android', 'iPhone', 'SymbianOS', 'Windows Phone', 'iPad', 'iPod']
let flag = true
for (let v = 0; v < Agents.length; v++) {
if (userAgentInfo.indexOf(Agents[v]) > 0) {
flag = false
break
}
}
return flag
}
判断是否为微信
export const isWx = () => { // 判断是否为微信
var ua = window.navigator.userAgent.toLowerCase()
if (ua.match(/MicroMessenger/i) === 'micromessenger') {
return true
}
return false
}
设备判断：android、ios、web
export const isDevice = function() { // 判断是android还是ios还是web
var ua = navigator.userAgent.toLowerCase()
if (ua.match(/iPhone\sOS/i) === 'iphone os' || ua.match(/iPad/i) === 'ipad') { // ios
return 'iOS'
}
if (ua.match(/Android/i) === 'android') {
return 'Android'
}
return 'Web'
}
常见正则校验
/*正则匹配*/
export const normalReg = (str, type) => {
switch (type) {
case 'phone': //手机号码
return /^1[3|4|5|6|7|8|9][0-9]{9}$/.test(str);
case 'tel': //座机
return /^(0\d{2,3}-\d{7,8})(-\d{1,4})?$/.test(str);
case 'card': //身份证
return /(^\d{15}$)|(^\d{18}$)|(^\d{17}(\d|X|x)$)/.test(str);
case 'pwd': //密码以字母开头，长度在6~18之间，只能包含字母、数字和下划线
return /^[a-zA-Z]\w{5,17}$/.test(str)
case 'postal': //邮政编码
return /[1-9]\d{5}(?!\d)/.test(str);
case 'QQ': //QQ号
return /^[1-9][0-9]{4,9}$/.test(str);
case 'email': //邮箱
return /^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$/.test(str);
case 'money': //金额(小数点2位)
return /^\d*(?:\.\d{0,2})?$/.test(str);
case 'URL': //网址
return /(http|ftp|https):\/\/[\w\-_]+(\.[\w\-_]+)+([\w\-\.,@?^=%&:/~\+#]*[\w\-\@?^=%&/~\+#])?/.test(str)
case 'IP': //IP
return /((?:(?:25[0-5]|2[0-4]\\d|[01]?\\d?\\d)\\.){3}(?:25[0-5]|2[0-4]\\d|[01]?\\d?\\d))/.test(str);
case 'date': //日期时间
return /^(\d{4})\-(\d{2})\-(\d{2}) (\d{2})(?:\:\d{2}|:(\d{2}):(\d{2}))$/.test(str) || /^(\d{4})\-(\d{2})\-(\d{2})$/.test(str)
case 'number': //数字
return /^[0-9]$/.test(str);
case 'positiveInteger': //正整数
return /^[1-9]\d*$/.test(str);
case 'price': //价格
return /(^[1-9]\d*(\.\d{1,2})?$)|(^0(\.\d{1,2})?$)/.test(str);//价格非0则去掉'?'
case 'english': //英文
return /^[a-zA-Z]+$/.test(str);
case 'chinese': //中文
return /^[\u4E00-\u9FA5]+$/.test(str);
case 'lower': //小写
return /^[a-z]+$/.test(str);
case 'upper': //大写
return /^[A-Z]+$/.test(str);
case 'HTML': //HTML标记
return /<("[^"]*"|'[^']*'|[^'">])*>/.test(str);
default:
return true;
}
}
去除字符串空格
/**
* @param {str} str
* @param {Number} type 1 -> 所有空格 2 -> 前后空格 3 -> 前空格 4 -> 后空格
* @returns {String}
*/
export const trim = function(str, type) {
type = type || 1
switch (type) {
case 1:
return str.replace(/\s+/g, '')
case 2:
return str.replace(/(^\s*)|(\s*$)/g, '')
case 3:
return str.replace(/(^\s*)/g, '')
case 4:
return str.replace(/(\s*$)/g, '')
default:
return str
}
}
过滤html代码
export const filterTag = function(str) { // 过滤html代码(把<>转换)
str = str.replace(/&/ig, '&')
str = str.replace(/</ig, '<')
str = str.replace(/>/ig, '>')
str = str.replace(' ', ' ')
return str
}
生成随机数范围
export const random = function(min, max) { // 生成随机数范围
if (arguments.length === 2) {
return Math.floor(min + Math.random() * ((max + 1) - min))
} else {
return null
}
}
判断图片加载完成
export const imgLoadAll = function(arr, callback) { // 图片加载
let arrImg = []
for (let i = 0; i < arr.length; i++) {
let img = new Image()
img.src = arr[i]
img.onload = function() {
arrImg.push(this)
if (arrImg.length == arr.length) {
callback && callback()
}
}
}
}
光标所在位置插入字符
export const insertAtCursor = function(dom, val) { // 光标所在位置插入字符
if (document.selection) {
dom.focus()
let sel = document.selection.createRange()
sel.text = val
sel.select()
} else if (dom.selectionStart || dom.selectionStart == '0') {
let startPos = dom.selectionStart
let endPos = dom.selectionEnd
let restoreTop = dom.scrollTop
dom.value = dom.value.substring(0, startPos) + val + dom.value.substring(endPos, dom.value.length)
if (restoreTop > 0) {
dom.scrollTop = restoreTop
}
dom.focus()
dom.selectionStart = startPos + val.length
dom.selectionEnd = startPos + val.length
} else {
dom.value += val
dom.focus()
}
}
图片地址转base64
export const getBase64 = function(img) {
//传入图片路径，返回base64，使用getBase64(url).then(function(base64){},function(err){});
let getBase64Image = function(img, width, height) {
//width、height调用时传入具体像素值，控制大小,不传则默认图像大小
let canvas = document.createElement("canvas");
canvas.width = width ? width : img.width;
canvas.height = height ? height : img.height;
let ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
let dataURL = canvas.toDataURL();
return dataURL;
}
let image = new Image();
image.crossOrigin = '';
image.src = img;
let deferred = $.Deferred();
if (img) {
image.onload = function() {
deferred.resolve(getBase64Image(image));
}
return deferred.promise();
}
}
base64图片下载功能
export const downloadFile = (base64, fileName) => {
let base64ToBlob = (code) => {
let parts = code.split(';base64,');
let contentType = parts[0].split(':')[1];
let raw = window.atob(parts[1]);
let rawLength = raw.length;
let uInt8Array = new Uint8Array(rawLength);
for (let i = 0; i < rawLength; ++i) {
uInt8Array[i] = raw.charCodeAt(i);
}
return new Blob([uInt8Array], {
type: contentType
});
};
let aLink = document.createElement('a');
let blob = base64ToBlob(base64); //new Blob([content]);
let evt = document.createEvent("HTMLEvents");
evt.initEvent("click", true, true); //initEvent不加后两个参数在FF下会报错 事件类型，是否冒泡，是否阻止浏览器的默认行为
aLink.download = fileName;
aLink.href = URL.createObjectURL(blob);
aLink.click();
}
浏览器是否支持webP格式图片
export const webPBool = () => !![].map && document.createElement('canvas').toDataURL('image/webp').indexOf('data:image/webp') == 0
H5软键盘缩回、弹起回调
/* 当软件键盘弹起会改变当前 window.innerHeight
监听这个值变化 [downCb 当软键盘弹起后，缩回的回调,upCb 当软键盘弹起的回调] */
export function(downCb, upCb) {
var clientHeight = window.innerHeight
downCb = typeof downCb === 'function' ? downCb : function() {}
upCb = typeof upCb === 'function' ? upCb : function() {}
window.addEventListener('resize', () => {
var height = window.innerHeight
if (height === clientHeight) {
downCb()
}
if (height < clientHeight) {
upCb()
}
})
}
对象属性剔除
/**
* @param {object} object
* @param {string[]} props
* @return {object}
*/
function omit(object, props=[]){
let res = {}
Object.keys(object).forEach(key=>{
if(props.includes(key) === false){
res[key] = typeof object[key] === 'object' && object[key] !== null ? jsON.parse(jsON.stringify(object[key])) : object[key]
}
})
return res
}
// for example
let data = { id: 1, title: '12345', name: '男'}
omit(data, ['id'])
// data ---> {title: 'xxx', name: '男'}
深拷贝
/**
* This is just a simple version of deep copy
* Has a lot of edge cases bug
* If you want to use a perfect deep copy, use lodash's _.cloneDeep
* @param {Object} source
* @returns {Object}
*/
export function deepClone(source) {
if (!source && typeof source !== 'object') {
throw new Error('error arguments', 'deepClone')
}
const targetObj = source.constructor === Array ? [] : {}
Object.keys(source).forEach(keys => {
if (source[keys] && typeof source[keys] === 'object') {
targetObj[keys] = deepClone(source[keys])
} else {
targetObj[keys] = source[keys]
}
})
return targetObj
}
函数防抖
export function debounce(func, wait, immediate) {
let timeout, args, context, timestamp, result
const later = function() {
// 据上一次触发时间间隔
const last = +new Date() - timestamp
// 上次被包装函数被调用时间间隔 last 小于设定时间间隔 wait
if (last < wait && last > 0) {
timeout = setTimeout(later, wait - last)
} else {
timeout = null
// 如果设定为immediate===true，因为开始边界已经调用过了此处无需调用
if (!immediate) {
result = func.apply(context, args)
if (!timeout) context = args = null
}
}
}
return function(...args) {
context = this
timestamp = +new Date()
const callNow = immediate && !timeout
// 如果延时不存在，重新设定延时
if (!timeout) timeout = setTimeout(later, wait)
if (callNow) {
result = func.apply(context, args)
context = args = null
}
return result
}
}
函数节流
/**
* @param {Function} func 目标函数
* @param {Number} wait 延迟执行毫秒数
* @param {Number} type type 1 表时间戳版，2 表定时器版
*/
export function(func, wait ,type) {
if(type===1){
let previous = 0;
}else if(type===2){
let timeout;
}
return function() {
let context = this;
let args = arguments;
if(type===1){
let now = Date.now();
if (now - previous > wait) {
func.apply(context, args);
previous = now;
}
}else if(type===2){
if (!timeout) {
timeout = setTimeout(() => {
timeout = null;
func.apply(context, args)
}, wait)
}
}
}
}
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