日常开发中,面对各种不同的需求,我们经常会用到以前开发过的一些工具函数,把这些工具函数收集起来,将大大提高我们的开发效率。
export const typeOf = function(obj) {
return Object.prototype.toString.call(obj).slice(8, -1).toLowerCase()
}
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示例:
typeOf('树哥') // string
typeOf([]) // array
typeOf(new Date()) // date
typeOf(null) // null
typeOf(true) // boolean
typeOf(() => { }) // function
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export const debounce = (() => {
let timer = null
return (callback, wait = 800) => {
timer&&clearTimeout(timer)
timer = setTimeout(callback, wait)
}
})()
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示例:
如 vue 中使用
methods: {
loadList() {
debounce(() => {
console.log('加载数据')
}, 500)
}
}
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export const throttle = (() => {
let last = 0
return (callback, wait = 800) => {
let now = +new Date()
if (now - last > wait) {
callback()
last = now
}
}
})()
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export const hideMobile = (mobile) => {
return mobile.replace(/^(\d{3})\d{4}(\d{4})$/, "$1****$2")
}
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export const launchFullscreen = (element) => {
if (element.requestFullscreen) {
element.requestFullscreen()
} else if (element.mozRequestFullScreen) {
element.mozRequestFullScreen()
} else if (element.msRequestFullscreen) {
element.msRequestFullscreen()
} else if (element.webkitRequestFullscreen) {
element.webkitRequestFullScreen()
}
}
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export const exitFullscreen = () => {
if (document.exitFullscreen) {
document.exitFullscreen()
} else if (document.msExitFullscreen) {
document.msExitFullscreen()
} else if (document.mozCancelFullScreen) {
document.mozCancelFullScreen()
} else if (document.webkitExitFullscreen) {
document.webkitExitFullscreen()
}
}
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参数:
str 待转换的字符串
type 1-全大写 2-全小写 3-首字母大写
export const turnCase = (str, type) => {
switch (type) {
case 1:
return str.toUpperCase()
case 2:
return str.toLowerCase()
case 3:
//return str[0].toUpperCase() + str.substr(1).toLowerCase() // substr 已不推荐使用
return str[0].toUpperCase() + str.substring(1).toLowerCase()
default:
return str
}
}
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示例:
turnCase('vue', 1) // VUE
turnCase('REACT', 2) // react
turnCase('vue', 3) // Vue
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export const getSearchParams = () => {
const searchPar = new URLSearchParams(window.location.search)
const paramsObj = {}
for (const [key, value] of searchPar.entries()) {
paramsObj[key] = value
}
return paramsObj
}
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示例:
// 假设目前位于 https://****com/index?id=154513&age=18;
getSearchParams(); // {id: "154513", age: "18"}
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/**
* 1: ios
* 2: android
* 3: 其它
*/
export const getOSType=() => {
let u = navigator.userAgent, app = navigator.appVersion;
let isAndroid = u.indexOf('Android') > -1 || u.indexOf('Linux') > -1;
let isIOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/);
if (isIOS) {
return 1;
}
if (isAndroid) {
return 2;
}
return 3;
}
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参数:
arr 要去重的数组
key 根据去重的字段名
export const uniqueArrayObject = (arr = [], key = 'id') => {
if (arr.length === 0) return
let list = []
const map = {}
arr.forEach((item) => {
if (!map[item[key]]) {
map[item[key]] = item
}
})
list = Object.values(map)
return list
}
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示例:
const responseList = [
{ id: 1, name: '树哥' },
{ id: 2, name: '黄老爷' },
{ id: 3, name: '张麻子' },
{ id: 1, name: '黄老爷' },
{ id: 2, name: '张麻子' },
{ id: 3, name: '树哥' },
{ id: 1, name: '树哥' },
{ id: 2, name: '黄老爷' },
{ id: 3, name: '张麻子' },
]
uniqueArrayObject(responseList, 'id')
// [{ id: 1, name: '树哥' },{ id: 2, name: '黄老爷' },{ id: 3, name: '张麻子' }]
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export const scrollToTop = () => {
const height = document.documentElement.scrollTop || document.body.scrollTop;
if (height > 0) {
window.requestAnimationFrame(scrollToTop);
window.scrollTo(0, height - height / 8);
}
}
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export const smoothScroll = element =>{
document.querySelector(element).scrollIntoView({
behavior: 'smooth'
});
};
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示例:
smoothScroll('#target'); // 平滑滚动到 ID 为 target 的元素
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export const uuid = () => {
const temp_url = URL.createObjectURL(new Blob())
const uuid = temp_url.toString()
URL.revokeObjectURL(temp_url) //释放这个url
return uuid.substring(uuid.lastIndexOf('/') + 1)
}
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示例:
uuid() // a640be34-689f-4b98-be77-e3972f9bffdd
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不过要吐槽一句的是,uuid一般应由后端来进行生成
参数:
{number} number:要格式化的数字
{number} decimals:保留几位小数
{string} dec_point:小数点符号
{string} thousands_sep:千分位符号
export const moneyFormat = (number, decimals, dec_point, thousands_sep) => {
number = (number + '').replace(/[^0-9+-Ee.]/g, '')
const n = !isFinite(+number) ? 0 : +number
const prec = !isFinite(+decimals) ? 2 : Math.abs(decimals)
const sep = typeof thousands_sep === 'undefined' ? ',' : thousands_sep
const dec = typeof dec_point === 'undefined' ? '.' : dec_point
let s = ''
const toFixedFix = function(n, prec) {
const k = Math.pow(10, prec)
return '' + Math.ceil(n * k) / k
}
s = (prec ? toFixedFix(n, prec) : '' + Math.round(n)).split('.')
const re = /(-?\d+)(\d{3})/
while (re.test(s[0])) {
s[0] = s[0].replace(re, '$1' + sep + '$2')
}
if ((s[1] || '').length < prec) {
s[1] = s[1] || ''
s[1] += new Array(prec - s[1].length + 1).join('0')
}
return s.join(dec)
}
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示例:
moneyFormat(10000000) // 10,000,000.00
moneyFormat(10000000, 3, '.', '-') // 10-000-000.000
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class MyCache {
constructor(isLocal = true) {
this.storage = isLocal ? localStorage : sessionStorage
}
setItem(key, value) {
if (typeof (value) === 'object') value = JSON.stringify(value)
this.storage.setItem(key, value)
}
getItem(key) {
try {
return JSON.parse(this.storage.getItem(key))
} catch (err) {
return this.storage.getItem(key)
}
}
removeItem(key) {
this.storage.removeItem(key)
}
clear() {
this.storage.clear()
}
key(index) {
return this.storage.key(index)
}
length() {
return this.storage.length
}
}
const localCache = new MyCache()
const sessionCache = new MyCache(false)
export { localCache, sessionCache }
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示例:
localCache.getItem('user')
sessionCache.setItem('name','树哥')
sessionCache.getItem('token')
localCache.clear()
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参数:
api 接口
params 请求参数
fileName 文件名
const downloadFile = (api, params, fileName, type = 'get') => {
axios({
method: type,
url: api,
responseType: 'blob',
params: params
}).then((res) => {
let str = res.headers['content-disposition']
if (!res || !str) {
return
}
let suffix = ''
// 截取文件名和文件类型
if (str.lastIndexOf('.')) {
fileName ? '' : fileName = decodeURI(str.substring(str.indexOf('=') + 1, str.lastIndexOf('.')))
suffix = str.substring(str.lastIndexOf('.'), str.length)
}
// 如果支持微软的文件下载方式(ie10+浏览器)
if (window.navigator.msSaveBlob) {
try {
const blobObject = new Blob([res.data]);
window.navigator.msSaveBlob(blobObject, fileName + suffix);
} catch (e) {
console.log(e);
}
} else {
// 其他浏览器
let url = window.URL.createObjectURL(res.data)
let link = document.createElement('a')
link.style.display = 'none'
link.href = url
link.setAttribute('download', fileName + suffix)
document.body.appendChild(link)
link.click()
document.body.removeChild(link)
window.URL.revokeObjectURL(link.href);
}
}).catch((err) => {
console.log(err.message);
})
}`
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使用:
downloadFile('/api/download', {id}, '文件名')
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关于时间操作,没必要自己再写一大串代码了,强烈推荐使用 day.js[2]
Day.js 是一个仅 2kb 大小的轻量级 JavaScript 时间日期处理库,下载、解析和执行的JavaScript更少,为代码留下更多的时间。
export const clone = parent => {
// 判断类型
const isType = (obj, type) => {
if (typeof obj !== "object") return false;
const typeString = Object.prototype.toString.call(obj);
let flag;
switch (type) {
case "Array":
flag = typeString === "[object Array]";
break;
case "Date":
flag = typeString === "[object Date]";
break;
case "RegExp":
flag = typeString === "[object RegExp]";
break;
default:
flag = false;
}
return flag;
};
// 处理正则
const getRegExp = re => {
var flags = "";
if (re.global) flags += "g";
if (re.ignoreCase) flags += "i";
if (re.multiline) flags += "m";
return flags;
};
// 维护两个储存循环引用的数组
const parents = [];
const children = [];
const _clone = parent => {
if (parent === null) return null;
if (typeof parent !== "object") return parent;
let child, proto;
if (isType(parent, "Array")) {
// 对数组做特殊处理
child = [];
} else if (isType(parent, "RegExp")) {
// 对正则对象做特殊处理
child = new RegExp(parent.source, getRegExp(parent));
if (parent.lastIndex) child.lastIndex = parent.lastIndex;
} else if (isType(parent, "Date")) {
// 对Date对象做特殊处理
child = new Date(parent.getTime());
} else {
// 处理对象原型
proto = Object.getPrototypeOf(parent);
// 利用Object.create切断原型链
child = Object.create(proto);
}
// 处理循环引用
const index = parents.indexOf(parent);
if (index != -1) {
// 如果父数组存在本对象,说明之前已经被引用过,直接返回此对象
return children[index];
}
parents.push(parent);
children.push(child);
for (let i in parent) {
// 递归
child[i] = _clone(parent[i]);
}
return child;
};
return _clone(parent);
};
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此方法存在一定局限性:一些特殊情况没有处理: 例如Buffer对象、Promise、Set、Map。
如果确实想要完备的深拷贝,推荐使用 lodash 中的 cloneDeep 方法。
参数:
list 原数组
keyWord 查询的关键词
attribute 数组需要检索属性
export const fuzzyQuery = (list, keyWord, attribute = 'name') => {
const reg = new RegExp(keyWord)
const arr = []
for (let i = 0; i < list.length; i++) {
if (reg.test(list[i][attribute])) {
arr.push(list[i])
}
}
return arr
}
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示例:
const list = [
{ id: 1, name: '树哥' },
{ id: 2, name: '黄老爷' },
{ id: 3, name: '张麻子' },
{ id: 4, name: '汤师爷' },
{ id: 5, name: '胡万' },
{ id: 6, name: '花姐' },
{ id: 7, name: '小梅' }
]
fuzzyQuery(list, '树', 'name') // [{id: 1, name: '树哥'}]
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export const foreachTree = (data, callback, childrenName = 'children') => {
for (let i = 0; i < data.length; i++) {
callback(data[i])
if (data[i][childrenName] && data[i][childrenName].length > 0) {
foreachTree(data[i][childrenName], callback, childrenName)
}
}
}
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示例:
假设我们要从树状结构数据中查找 id 为 9 的节点
const treeData = [{
id: 1,
label: '一级 1',
children: [{
id: 4,
label: '二级 1-1',
children: [{
id: 9,
label: '三级 1-1-1'
}, {
id: 10,
label: '三级 1-1-2'
}]
}]
}, {
id: 2,
label: '一级 2',
children: [{
id: 5,
label: '二级 2-1'
}, {
id: 6,
label: '二级 2-2'
}]
}, {
id: 3,
label: '一级 3',
children: [{
id: 7,
label: '二级 3-1'
}, {
id: 8,
label: '二级 3-2'
}]
}],
let result
foreachTree(data, (item) => {
if (item.id === 9) {
result = item
}
})
console.log('result', result) // {id: 9,label: "三级 1-1-1"}
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---END---
来自:掘金,作者:呛再首
链接:https://juejin.cn/post/7132714583399071758