js常用工具类
常用工具类
Created: March 6, 2023 11:24 AM
Created By: breeze
Last Edited Time: March 6, 2023 12:08 PM
1.邮箱
export const isEmail = (s) => {
return /^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+((.[a-zA-Z0-9_-]{2,3}){1,2})$/.test(s)
}
2.手机号码
export const isMobile = (s) => {
return /^1[0-9]{10}$/.test(s)
}
3.电话号码
export const isPhone = (s) => {
return /^([0-9]{3,4}-)?[0-9]{7,8}$/.test(s)
}
4.是否url地址
export const isURL = (s) => {
return /^http[s]?:\/\/.*/.test(s)
}
5.是否字符串
export const isString = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'String'
}
6.是否数字
export const isNumber = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Number'
}
7.是否boolean
export const isBoolean = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Boolean'
}
8.是否函数
export const isFunction = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Function'
}
9.是否为null
export const isNull = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Null'
}
10.是否undefined
export const isUndefined = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Undefined'
}
11.是否对象
export const isObj = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Object'
}
12.是否数组
export const isArray = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Array'
}
13.是否时间
export const isDate = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Date'
}
14.是否正则
export const isRegExp = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'RegExp'
}
15.是否错误对象
export const isError = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Error'
}
16.是否Symbol函数
export const isSymbol = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Symbol'
}
17.是否Promise对象
export const isPromise = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Promise'
}
18.是否Set对象
export const isSet = (o) => {
return Object.prototype.toString.call(o).slice(8, -1) === 'Set'
}
export const ua = navigator.userAgent.toLowerCase();
19.是否是微信浏览器
export const isWeiXin = () => {
return ua.match(/microMessenger/i) == 'micromessenger'
}
20.是否是移动端
export const isDeviceMobile = () => {
return /android|webos|iphone|ipod|balckberry/i.test(ua)
}
21.是否是QQ浏览器
export const isQQBrowser = () => {
return !!ua.match(/mqqbrowser|qzone|qqbrowser|qbwebviewtype/i)
}
22.是否是爬虫
export const isSpider = () => {
return /adsbot|googlebot|bingbot|msnbot|yandexbot|baidubot|robot|careerbot|seznambot|bot|baiduspider|jikespider|symantecspider|scannerlwebcrawler|crawler|360spider|sosospider|sogou web sprider|sogou orion spider/.test(ua)
}
23.是否ios
export const isIos = () => {
var u = navigator.userAgent;
if (u.indexOf('Android') > -1 || u.indexOf('Linux') > -1) { //安卓手机
return false
} else if (u.indexOf('iPhone') > -1) {//苹果手机
return true
} else if (u.indexOf('iPad') > -1) {//iPad
return false
} else if (u.indexOf('Windows Phone') > -1) {//winphone手机
return false
} else {
return false
}
}
24.是否为PC端
export const isPC = () => {
var userAgentInfo = navigator.userAgent;
var Agents = ["Android", "iPhone",
"SymbianOS", "Windows Phone",
"iPad", "iPod"];
var flag = true;
for (var v = 0; v < Agents.length; v++) {
if (userAgentInfo.indexOf(Agents[v]) > 0) {
flag = false;
break;
}
}
return flag;
}
25.去除html标签
export const removeHtmltag = (str) => {
return str.replace(/<[^>]+>/g, '')
}
26.获取url参数
export const getQueryString = (name) => {
const reg = new RegExp('(^|&)' + name + '=([^&]*)(&|$)', 'i');
const search = window.location.search.split('?')[1] || '';
const r = search.match(reg) || [];
return r[2];
}
27.动态引入js
export const injectScript = (src) => {
const s = document.createElement('script');
s.type = 'text/javascript';
s.async = true;
s.src = src;
const t = document.getElementsByTagName('script')[0];
t.parentNode.insertBefore(s, t);
}
28.根据url地址下载
export const download = (url) => {
var isChrome = navigator.userAgent.toLowerCase().indexOf('chrome') > -1;
var isSafari = navigator.userAgent.toLowerCase().indexOf('safari') > -1;
if (isChrome || isSafari) {
var link = document.createElement('a');
link.href = url;
if (link.download !== undefined) {
var fileName = url.substring(url.lastIndexOf('/') + 1, url.length);
link.download = fileName;
}
if (document.createEvent) {
var e = document.createEvent('MouseEvents');
e.initEvent('click', true, true);
link.dispatchEvent(e);
return true;
}
}
if (url.indexOf('?') === -1) {
url += '?download';
}
window.open(url, '_self');
return true;
}
29.el是否包含某个class
export const hasClass = (el, className) => {
let reg = new RegExp('(^|\s)' + className + '(\s|$)')
return reg.test(el.className)
}
30.el添加某个class
export const addClass = (el, className) => {
if (hasClass(el, className)) {
return
}
let newClass = el.className.split(' ')
newClass.push(className)
el.className = newClass.join(' ')
}
31.el去除某个class
export const removeClass = (el, className) => {
if (!hasClass(el, className)) {
return
}
let reg = new RegExp('(^|\\s)' + className + '(\\s|$)', 'g')
el.className = el.className.replace(reg, ' ')
}
32.获取滚动的坐标
export const getScrollPosition = (el = window) => ({
x: el.pageXOffset !== undefined ? el.pageXOffset : el.scrollLeft,
y: el.pageYOffset !== undefined ? el.pageYOffset : el.scrollTop
});
33.滚动到顶部
export const scrollToTop = () => {
const c = document.documentElement.scrollTop || document.body.scrollTop;
if (c > 0) {
window.requestAnimationFrame(scrollToTop);
window.scrollTo(0, c - c / 8);
}
}
34.el是否在视口范围内
export const elementIsVisibleInViewport = (el, partiallyVisible = false) => {
const { top, left, bottom, right } = el.getBoundingClientRect();
const { innerHeight, innerWidth } = window;
return partiallyVisible
? ((top > 0 && top < innerHeight) || (bottom > 0 && bottom < innerHeight)) &&
((left > 0 && left < innerWidth) || (right > 0 && right < innerWidth))
: top >= 0 && left >= 0 && bottom <= innerHeight && right <= innerWidth;
}
35.洗牌算法随机
export const shuffle = (arr) => {
var result = [],
random;
while (arr.length > 0) {
random = Math.floor(Math.random() * arr.length);
result.push(arr[random])
arr.splice(random, 1)
}
return result;
}
36.拦截粘贴板
export const copyTextToClipboard = (value) => {
var textArea = document.createElement("textarea");
textArea.style.background = 'transparent';
textArea.value = value;
document.body.appendChild(textArea);
textArea.select();
try {
var successful = document.execCommand('copy');
} catch (err) {
console.log('Oops, unable to copy');
}
document.body.removeChild(textArea);
}
37.判断类型集合
export const checkStr = (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 '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;
}
}
38.严格的身份证校验
export const isCardID = (sId) => {
if (!/(^\d{15}$)|(^\d{17}(\d|X|x)$)/.test(sId)) {
console.log('你输入的身份证长度或格式错误')
return false
}
//身份证城市
var aCity = { 11: "北京", 12: "天津", 13: "河北", 14: "山西", 15: "内蒙古", 21: "辽宁", 22: "吉林", 23: "黑龙江", 31: "上海", 32: "江苏", 33: "浙江", 34: "安徽", 35: "福建", 36: "江西", 37: "山东", 41: "河南", 42: "湖北", 43: "湖南", 44: "广东", 45: "广西", 46: "海南", 50: "重庆", 51: "四川", 52: "贵州", 53: "云南", 54: "西藏", 61: "陕西", 62: "甘肃", 63: "青海", 64: "宁夏", 65: "新疆", 71: "台湾", 81: "香港", 82: "澳门", 91: "国外" };
if (!aCity[parseInt(sId.substr(0, 2))]) {
console.log('你的身份证地区非法')
return false
}
// 出生日期验证
var sBirthday = (sId.substr(6, 4) + "-" + Number(sId.substr(10, 2)) + "-" + Number(sId.substr(12, 2))).replace(/-/g, "/"),
d = new Date(sBirthday)
if (sBirthday != (d.getFullYear() + "/" + (d.getMonth() + 1) + "/" + d.getDate())) {
console.log('身份证上的出生日期非法')
return false
}
// 身份证号码校验
var sum = 0,
weights = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2],
codes = "10X98765432"
for (var i = 0; i < sId.length - 1; i++) {
sum += sId[i] * weights[i];
}
var last = codes[sum % 11]; //计算出来的最后一位身份证号码
if (sId[sId.length - 1] != last) {
console.log('你输入的身份证号非法')
return false
}
return true
}
39.随机数范围
export const random = (min, max) => {
if (arguments.length === 2) {
return Math.floor(min + Math.random() * ((max + 1) - min))
} else {
return null;
}
}
40.将阿拉伯数字翻译成中文的大写数字
export const numberToChinese = (num) => {
var AA = new Array("零", "一", "二", "三", "四", "五", "六", "七", "八", "九", "十");
var BB = new Array("", "十", "百", "仟", "萬", "億", "点", "");
var a = ("" + num).replace(/(^0*)/g, "").split("."),
k = 0,
re = "";
for (var i = a[0].length - 1; i >= 0; i--) {
switch (k) {
case 0:
re = BB[7] + re;
break;
case 4:
if (!new RegExp("0{4}//d{" + (a[0].length - i - 1) + "}$")
.test(a[0]))
re = BB[4] + re;
break;
case 8:
re = BB[5] + re;
BB[7] = BB[5];
k = 0;
break;
}
if (k % 4 == 2 && a[0].charAt(i + 2) != 0 && a[0].charAt(i + 1) == 0)
re = AA[0] + re;
if (a[0].charAt(i) != 0)
re = AA[a[0].charAt(i)] + BB[k % 4] + re;
k++;
}
if (a.length > 1) // 加上小数部分(如果有小数部分)
{
re += BB[6];
for (var i = 0; i < a[1].length; i++)
re += AA[a[1].charAt(i)];
}
if (re == '一十')
re = "十";
if (re.match(/^一/) && re.length == 3)
re = re.replace("一", "");
return re;
}
41.将数字转换为大写金额
export const changeToChinese = (Num) => {
//判断如果传递进来的不是字符的话转换为字符
if (typeof Num == "number") {
Num = new String(Num);
};
Num = Num.replace(/,/g, "") //替换tomoney()中的“,”
Num = Num.replace(/ /g, "") //替换tomoney()中的空格
Num = Num.replace(/￥/g, "") //替换掉可能出现的￥字符
if (isNaN(Num)) { //验证输入的字符是否为数字
//alert("请检查小写金额是否正确");
return "";
};
//字符处理完毕后开始转换，采用前后两部分分别转换
var part = String(Num).split(".");
var newchar = "";
//小数点前进行转化
for (var i = part[0].length - 1; i >= 0; i--) {
if (part[0].length > 10) {
return "";
//若数量超过拾亿单位，提示
}
var tmpnewchar = ""
var perchar = part[0].charAt(i);
switch (perchar) {
case "0":
tmpnewchar = "零" + tmpnewchar;
break;
case "1":
tmpnewchar = "壹" + tmpnewchar;
break;
case "2":
tmpnewchar = "贰" + tmpnewchar;
break;
case "3":
tmpnewchar = "叁" + tmpnewchar;
break;
case "4":
tmpnewchar = "肆" + tmpnewchar;
break;
case "5":
tmpnewchar = "伍" + tmpnewchar;
break;
case "6":
tmpnewchar = "陆" + tmpnewchar;
break;
case "7":
tmpnewchar = "柒" + tmpnewchar;
break;
case "8":
tmpnewchar = "捌" + tmpnewchar;
break;
case "9":
tmpnewchar = "玖" + tmpnewchar;
break;
}
switch (part[0].length - i - 1) {
case 0:
tmpnewchar = tmpnewchar + "元";
break;
case 1:
if (perchar != 0) tmpnewchar = tmpnewchar + "拾";
break;
case 2:
if (perchar != 0) tmpnewchar = tmpnewchar + "佰";
break;
case 3:
if (perchar != 0) tmpnewchar = tmpnewchar + "仟";
break;
case 4:
tmpnewchar = tmpnewchar + "万";
break;
case 5:
if (perchar != 0) tmpnewchar = tmpnewchar + "拾";
break;
case 6:
if (perchar != 0) tmpnewchar = tmpnewchar + "佰";
break;
case 7:
if (perchar != 0) tmpnewchar = tmpnewchar + "仟";
break;
case 8:
tmpnewchar = tmpnewchar + "亿";
break;
case 9:
tmpnewchar = tmpnewchar + "拾";
break;
}
var newchar = tmpnewchar + newchar;
}
//小数点之后进行转化
if (Num.indexOf(".") != -1) {
if (part[1].length > 2) {
// alert("小数点之后只能保留两位,系统将自动截断");
part[1] = part[1].substr(0, 2)
}
for (i = 0; i < part[1].length; i++) {
tmpnewchar = ""
perchar = part[1].charAt(i)
switch (perchar) {
case "0":
tmpnewchar = "零" + tmpnewchar;
break;
case "1":
tmpnewchar = "壹" + tmpnewchar;
break;
case "2":
tmpnewchar = "贰" + tmpnewchar;
break;
case "3":
tmpnewchar = "叁" + tmpnewchar;
break;
case "4":
tmpnewchar = "肆" + tmpnewchar;
break;
case "5":
tmpnewchar = "伍" + tmpnewchar;
break;
case "6":
tmpnewchar = "陆" + tmpnewchar;
break;
case "7":
tmpnewchar = "柒" + tmpnewchar;
break;
case "8":
tmpnewchar = "捌" + tmpnewchar;
break;
case "9":
tmpnewchar = "玖" + tmpnewchar;
break;
}
if (i == 0) tmpnewchar = tmpnewchar + "角";
if (i == 1) tmpnewchar = tmpnewchar + "分";
newchar = newchar + tmpnewchar;
}
}
//替换所有无用汉字
while (newchar.search("零零") != -1)
newchar = newchar.replace("零零", "零");
newchar = newchar.replace("零亿", "亿");
newchar = newchar.replace("亿万", "亿");
newchar = newchar.replace("零万", "万");
newchar = newchar.replace("零元", "元");
newchar = newchar.replace("零角", "");
newchar = newchar.replace("零分", "");
if (newchar.charAt(newchar.length - 1) == "元") {
newchar = newchar + "整"
}
return newchar;
}
42.判断一个元素是否在数组中
export const contains = (arr, val) => {
return arr.indexOf(val) != -1 ? true : false;
}
43.数组排序，{type} 1：从小到大 2：从大到小 3：随机
export const sort = (arr, type = 1) => {
return arr.sort((a, b) => {
switch (type) {
case 1:
return a - b;
case 2:
return b - a;
case 3:
return Math.random() - 0.5;
default:
return arr;
}
})
}
44.去重
export const unique = (arr) => {
if (Array.hasOwnProperty('from')) {
return Array.from(new Set(arr));
} else {
var n = {}, r = [];
for (var i = 0; i < arr.length; i++) {
if (!n[arr[i]]) {
n[arr[i]] = true;
r.push(arr[i]);
}
}
return r;
}
}
45.求两个集合的并集
export const union = (a, b) => {
var newArr = a.concat(b);
return this.unique(newArr);
}
46.求两个集合的交集
export const intersect = (a, b) => {
var _this = this;
a = this.unique(a);
return this.map(a, function (o) {
return _this.contains(b, o) ? o : null;
});
}
47.删除其中一个元素
export const remove = (arr, ele) => {
var index = arr.indexOf(ele);
if (index > -1) {
arr.splice(index, 1);
}
return arr;
}
48.将类数组转换为数组
export const formArray = (ary) => {
var arr = [];
if (Array.isArray(ary)) {
arr = ary;
} else {
arr = Array.prototype.slice.call(ary);
};
return arr;
}
49.最大值
export const max = (arr) => {
return Math.max.apply(null, arr);
}
50.最小值
export const min = (arr) => {
return Math.min.apply(null, arr);
}
51.求和
export const sum = (arr) => {
return arr.reduce((pre, cur) => {
return pre + cur
})
}
52.平均值
export const average = (arr) => {
return this.sum(arr) / arr.length
}
53.去除空格,type: 1-所有空格 2-前后空格 3-前空格 4-后空格
export const trim = (str, type) => {
type = type || 1
switch (type) {
case 1:
return str.replace(/\s+/g, "");
case 2:
return str.replace(/(^\s*)|(\s*%2Fg%2C%20%22%22)%3B%20case%203%3A%20return%20str.replace(%2F(%5E%5Cs*)%2Fg%2C%20%22%22)%3B%20case%204%3A%20return%20str.replace(%2F(%5Cs*))/g, "");
default:
return str;
}
}
54.字符转换
type: 1:首字母大写 2：首字母小写 3：大小写转换 4：全部大写 5：全部小写
export const changeCase = (str, type) => {
type = type || 4
switch (type) {
case 1:
return str.replace(/\b\w+\b/g, function (word) {
return word.substring(0, 1).toUpperCase() + word.substring(1).toLowerCase();
});
case 2:
return str.replace(/\b\w+\b/g, function (word) {
return word.substring(0, 1).toLowerCase() + word.substring(1).toUpperCase();
});
case 3:
return str.split('').map(function (word) {
if (/[a-z]/.test(word)) {
return word.toUpperCase();
} else {
return word.toLowerCase()
}
}).join('')
case 4:
return str.toUpperCase();
case 5:
return str.toLowerCase();
default:
return str;
}
}
55.检测密码强度
export const checkPwd = (str) => {
var Lv = 0;
if (str.length < 6) {
return Lv
}
if (/[0-9]/.test(str)) {
Lv++
}
if (/[a-z]/.test(str)) {
Lv++
}
if (/[A-Z]/.test(str)) {
Lv++
}
if (/[.|-|_]/.test(str)) {
Lv++
}
return Lv;
}
56.函数节流器
export const debouncer = (fn, time, interval = 200) => {
if (time - (window.debounceTimestamp || 0) > interval) {
fn && fn();
window.debounceTimestamp = time;
}
}
57.在字符串中插入新字符串
export const insertStr = (soure, index, newStr) => {
var str = soure.slice(0, index) + newStr + soure.slice(index);
return str;
}
58.判断两个对象是否键值相同
export const isObjectEqual = (a, b) => {
var aProps = Object.getOwnPropertyNames(a);
var bProps = Object.getOwnPropertyNames(b);
if (aProps.length !== bProps.length) {
return false;
}
for (var i = 0; i < aProps.length; i++) {
var propName = aProps[i];
if (a[propName] !== b[propName]) {
return false;
}
}
return true;
}
59.16进制颜色转RGBRGBA字符串
export const colorToRGB = (val, opa) => {
var pattern = /^(#?)[a-fA-F0-9]{6}$/; //16进制颜色值校验规则
var isOpa = typeof opa == 'number'; //判断是否有设置不透明度
if (!pattern.test(val)) { //如果值不符合规则返回空字符
return '';
}
var v = val.replace(/#/, ''); //如果有#号先去除#号
var rgbArr = [];
var rgbStr = '';
for (var i = 0; i < 3; i++) {
var item = v.substring(i * 2, i * 2 + 2);
var num = parseInt(item, 16);
rgbArr.push(num);
}
rgbStr = rgbArr.join();
rgbStr = 'rgb' + (isOpa ? 'a' : '') + '(' + rgbStr + (isOpa ? ',' + opa : '') + ')';
return rgbStr;
}
60.追加url参数
export const appendQuery = (url, key, value) => {
var options = key;
if (typeof options == 'string') {
options = {};
options[key] = value;
}
options = $.param(options);
if (url.includes('?')) {
url += '&' + options
} else {
url += '?' + options
}
return url;
}
1. 知道一个日期是否对应于当前日期
就像将两个日期转换为相同格式并进行比较一样简单。
const isCurrentDay = (date) => new Date().toISOString().slice(0, 10) === date.toISOString().slice(0, 10);
2.如何知道一个日期是否在两个日期之间
我们检查过去的日期是否在最小-最大范围内。
const isBetweenTwoDates = ( min, max, date) => date.getTime() >= min.getTime() && date.getTime() <= max.getTime();
3. 如何知道约会是否在周末
getDay 方法返回一个介于 0 和 6 之间的数字，表示给定日期是星期几。
const isWeekend = ( date ) => date.getDay() === 6 || date.getDay() === 0;
4. 检查日期是否在一年内
类似于我们过去检查日期是否与当前日期相对应的情况。在这种情况下，我们获取年份并进行比较。
const isInAYear = (date, year) => date.getUTCFullYear() === new Date(`${year}`).getUTCFullYear();
5. 将小时转换为 AM-PM 格式
我们可以用数学表达式来判断经过的时间是否小于或等于13小时，从而判断是“上午”还是“下午”。
const toAMPMFormat= (h) => `${h % 12 === 0 ? 12 : h % 12}${h < 12 ? ' am.' : ' pm.'}`;
字符串
6.句子首字母大写
我们将第一个字母转换为大写字母，然后使用 <join.> 附加句子的其余字母
const capitalize = ([first, ...rest]) => `${first.toUpperCase()}${rest.join('')}`;
7.将一封信转换成他的同事表情符号
const letterToEmoji = c => String.fromCodePoint(c.toLowerCase().charCodeAt() + 127365);
8. 如何判断一个字符串是不是回文
const isPalindrome = (str) => str.toLowerCase() === str.toLowerCase().split('').reverse().join('');
数字
9. 如何计算一个数的阶乘
const getFactorial = (n) => (n <= 1 ? 1 : n * getFactorial(n - 1));
10. 如何获得一个数的斐波那契数列
const getFibonacci = (n, memo = {}) => memo[n] || (n <= 2 ? 1 : (memo[n] = getFibonacci(n - 1, memo) + getFibonacci(n - 2, memo)));
11.如何求一个数的阶乘
const getFactorial = (n) => (n <= 1 ? 1 : n * getFactorial(n - 1));
数组
12.将一个数组复制到另一个数组
const copyToArray = (arr) => [...arr];
13. 从数组中获取唯一元素
const getUnique = (arr) => [...new Set(arr)];
14. 随机排列
以下代码段以非常有效的方式打乱数组。
const shuffle = (arr) => arr.sort(() => Math.random() - 0.5);
15. 按属性对数组进行分组
const groupBy = (arr, groupFn) => arr.reduce( (grouped, obj) => ({...grouped, [groupFn(obj)]: [...(grouped[groupFn(obj)] || []), obj], }),{});
16. 反转字符串
我们可以利用内置的 Array 方法，如 reverse() 和 join() 来创建一个做同样事情的单行代码。
const reverseString = (str) => str.split('').reverse().join('');
17. 检查两个数组是否包含相同的值
我们可以使用 Array.sort() 和 Array.join() 方法来检查两个数组是否包含相同的值。
const containSameValues= (arr1, arr2) => arr1.sort().join(',') === arr2.sort().join(',');
工具
18. 转换为华氏温度
const toFahrenheit= (celsius) => (celsius * 9) / 5 + 32;
19. 转换为摄氏度
const toCelsius= (fahrenheit) => (fahrenheit- 32) * 5 / 9;
20. 如何清除浏览器的所有cookies
const clearAllCookies = () => document.cookie.split(';').forEach((c) => (document.cookie = c.replace(/^ +/, '').replace(/=.*/, `=;expires=${new Date().toUTCString()};path=/`)));
21. 如何将 HEX 转换为 RGB
const toRGB= (hex) => hex .replace(/^#?([a-f\d])([a-f\d])([a-f\d])$/i, (_, r, g, b) => `#${r}${r}${g}${g}${b}${b}`) .substring(1) .match(/.{2}/g) .map((x) => parseInt(x, 16));
22. 如何将 RGB 转换为 HEX
const toHEX = (r,g,b) => "#" + ((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1);
23. 检查函数是否为异步函数
const isAsyncFunction = (f) => Object.prototype.toString.call(f) === '[object AsyncFunction]';
24.如何知道一段代码是否在浏览器中运行
const runningInBrowser = typeof window === 'object' && typeof document === 'object';
25.如何知道一段代码是否在node中运行
const runningInNode= typeof process !== 'undefined' && process.versions != null && process.versions.node != null;
26.检测暗模式
这是一种非常方便的方法来检查用户是否在其浏览器上启用了黑暗模式。
const isDarkMode = () => window.matchMedia && window.matchMedia("(prefers-color-scheme: dark)").matches;
27.滚动到顶部
滚动元素的一种单行方法是使用
const toTop = (element) => element.scrollIntoView({ behavior: "smooth", block: "start" });
28.滚动到底部
const toBottom = (element) => element.scrollIntoView({ behavior: "smooth", block: "end" });
29. 将 JSON 转换为map
这个函数可以让我们以简单的方式将 Map 对象转换为 JSON 字符串。
const jsonToMap = (json) => new Map(Object.entries(JSON.parse(json)));
30.生成一个128位的UUID
此函数允许我们生成具有 128 位值的 UUID，用于唯一标识对象或实体。
const generateUUID = (a) => a ? (a ^ ((Math.random() * 16) >> (a / 4))).toString(16) : ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace( /[018]/g, generateUUID);
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