「JavaScript」56 个 JavaScript 实用工具函数助你提升开发效率

1. 数字操作

（1）生成指定范围随机数

export const randomNum = (min, max) => Math.floor(Math.random() * (max - min + 1)) + min;

（2）数字千分位分隔

export const format = (n) => {
    let num = n.toString();
    let len = num.length;
    if (len <= 3) {
        return num;
    } else {
        let temp = '';
        let remainder = len % 3;
        if (remainder > 0) { // 不是3的整数倍
            return num.slice(0, remainder) + ',' + num.slice(remainder, len).match(/\d{3}/g).join(',') + temp;
        } else { // 3的整数倍
            return num.slice(0, len).match(/\d{3}/g).join(',') + temp; 
        }
    }
}

（3）大整数相加

/**
 * 腾讯基础面试题
 * 两个超过整数存储范围的大正整数求和
 * @param {String} a
 * @param {String} b
 */
function sum(a, b){
    const len = Math.max(a.length, b.length);
    a = a.padStart(len, '0');
    b = b.padStart(len, '0');
    let result = '';
    let carry = 0;
    for(let i = len - 1; i >= 0; i--){
        const sum = parseInt(a[i]) + parseInt(b[i]) + carry;
        result = (sum % 10) + result;
        carry = Math.floor(sum / 10);
    }
    return carry ? carry + result : result;
}

2. 数组操作

（1）数组乱序

export const arrScrambling = (arr) => {
    for (let i = 0; i < arr.length; i++) {
      const randomIndex = Math.round(Math.random() * (arr.length - 1 - i)) + i;
      [arr[i], arr[randomIndex]] = [arr[randomIndex], arr[i]];
    }
    return arr;
}

（2）数组扁平化

export const flatten = (arr) => {
  let result = [];

  for(let i = 0; i < arr.length; i++) {
    if(Array.isArray(arr[i])) {
      result = result.concat(flatten(arr[i]));
    } else {
      result.push(arr[i]);
    }
  }
  return result;
}

（3）数组中获取随机数

export const sample = arr => arr[Math.floor(Math.random() * arr.length)]; 

3. 字符串操作

（1）生成随机字符串

export const randomString = (len) => {
    let chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz123456789';
    let strLen = chars.length;
    let randomStr = '';
    for (let i = 0; i < len; i++) {
        randomStr += chars.charAt(Math.floor(Math.random() * strLen));
    }
    return randomStr;
};

（2）字符串首字母大写

export const fistLetterUpper = (str) => {
    return str.charAt(0).toUpperCase() + str.slice(1);
};

（3）手机号中间四位变成*

export const telFormat = (tel) => {
   tel = String(tel); 
    return tel.substr(0,3) + "****" + tel.substr(7);
};

（4）驼峰命名转换成短横线命名

export const getKebabCase = (str) => {
    return str.replace(/[A-Z]/g, (item) => '-' + item.toLowerCase())
}

（5）短横线命名转换成驼峰命名

export const getCamelCase = (str) => {
    return str.replace( /-([a-z])/g, (i, item) => item.toUpperCase())
}

（6）全角转换为半角

export const toCDB = (str) => {
  let result = "";
  for (let i = 0; i < str.length; i++) {
    code = str.charCodeAt(i);
    if (code >= 65281 && code <= 65374) {
      result += String.fromCharCode(str.charCodeAt(i) - 65248);
    } else if (code == 12288) {
      result += String.fromCharCode(str.charCodeAt(i) - 12288 + 32);
    } else {
      result += str.charAt(i);
    }
  }
  return result;
}

（7）半角转换为全角

export const toDBC = (str) => {
  let result = "";
  for (let i = 0; i < str.length; i++) {
    code = str.charCodeAt(i);
    if (code >= 33 && code <= 126) {
      result += String.fromCharCode(str.charCodeAt(i) + 65248);
    } else if (code == 32) {
      result += String.fromCharCode(str.charCodeAt(i) + 12288 - 32);
    } else {
      result += str.charAt(i);
    }
  }
  return result;
}

4. 格式转化

（1）数字转化为大写金额

export const digitUppercase = (n) => {
    const fraction = ['角', '分'];
    const digit = [
        '零', '壹', '贰', '叁', '肆',
        '伍', '陆', '柒', '捌', '玖'
    ];
    const unit = [
        ['元', '万', '亿'],
        ['', '拾', '佰', '仟']
    ];
    n = Math.abs(n);
    let s = '';
    for (let i = 0; i < fraction.length; i++) {
        s += (digit[Math.floor(n * 10 * Math.pow(10, i)) % 10] + fraction[i]).replace(/零./, '');
    }
    s = s || '整';
    n = Math.floor(n);
    for (let i = 0; i < unit[0].length && n > 0; i++) {
        let p = '';
        for (let j = 0; j < unit[1].length && n > 0; j++) {
            p = digit[n % 10] + unit[1][j] + p;
            n = Math.floor(n / 10);
        }
        s = p.replace(/(零.)*零$/, '').replace(/^$/, '零') + unit[0][i] + s;
    }
    return s.replace(/(零.)*零元/, '元')
        .replace(/(零.)+/g, '零')
        .replace(/^整$/, '零元整');
};

（2）数字转化为中文数字

export const intToChinese = (value) => {
 const str = String(value);
 const len = str.length-1;
 const idxs = ['','十','百','千','万','十','百','千','亿','十','百','千','万','十','百','千','亿'];
 const num = ['零','一','二','三','四','五','六','七','八','九'];
 return str.replace(/([1-9]|0+)/g, ( $, $1, idx, full) => {
    let pos = 0;
    if($1[0] !== '0'){
      pos = len-idx;
      if(idx == 0 && $1[0] == 1 && idxs[len-idx] == '十'){
        return idxs[len-idx];
      }
      return num[$1[0]] + idxs[len-idx];
    } else {
      let left = len - idx;
      let right = len - idx + $1.length;
      if(Math.floor(right / 4) - Math.floor(left / 4) > 0){
        pos = left - left % 4;
      }
      if( pos ){
        return idxs[pos] + num[$1[0]];
      } else if( idx + $1.length >= len ){
        return '';
      }else {
        return num[$1[0]]
      }
    }
   });
}

5. 操作存储

（1）存储loalStorage

export const loalStorageSet = (key, value) => {
    if (!key) return;
    if (typeof value !== 'string') {
        value = JSON.stringify(value);
    }
    window.localStorage.setItem(key, value);
};

（2）获取localStorage

export const loalStorageGet = (key) => {
    if (!key) return;
    return window.localStorage.getItem(key);
};

（3）删除localStorage

export const loalStorageRemove = (key) => {
    if (!key) return;
    window.localStorage.removeItem(key);
};

（4）存储sessionStorage

export const sessionStorageSet = (key, value) => {
   if (!key) return;
    if (typeof value !== 'string') {
      value = JSON.stringify(value);
    }
    window.sessionStorage.setItem(key, value)
};

（5）获取sessionStorage

export const sessionStorageGet = (key) => {
   if (!key) return;
    return window.sessionStorage.getItem(key)
};

（6）删除sessionStorage

export const sessionStorageRemove = (key) => {
   if (!key) return;
    window.sessionStorage.removeItem(key)
};

6. 操作cookie

（1）设置cookie

export const setCookie = (key, value, expire) => {
    const d = new Date();
    d.setDate(d.getDate() + expire);
    document.cookie = ${key}=${value};expires=${d.toUTCString()}
};

（2）读取cookie

export const getCookie = (key) => {
    const cookieStr = unescape(document.cookie);
       const arr = cookieStr.split('; ');
       let cookieValue = '';
       for (let i = 0; i < arr.length; i++) {
           const temp = arr[i].split('=');
           if (temp[0] === key) {
               cookieValue = temp[1];
               break
       }
    }
    return cookieValue
};

（3）删除cookie

export const checkCardNo = (value) => {
    let reg = /(^\d{15}$)|(^\d{18}$)|(^\d{17}(\d|X|x)$)/;
    return reg.test(value);
};

7. 格式校验

（1）校验身份证号码

export const checkCardNo = (value) => {
    let reg = /(^\d{15}$)|(^\d{18}$)|(^\d{17}(\d|X|x)$)/;
    return reg.test(value);
};

（2）校验是否包含中文

export const haveCNChars => (value) => {
    return /[\u4e00-\u9fa5]/.test(value);
}

（3）校验是否为中国大陆的邮政编码

export const isPostCode = (value) => {
    return /^[1-9][0-9]{5}$/.test(value.toString());
}

（4）校验是否为IPv6地址

export const isIPv6 = (str) => {
    return Boolean(str.match(/:/g)?str.match(/:/g).length<=7:false && /::/.test(str)?/^([\da-f]{1,4}(:|::)){1,6}[\da-f]{1,4}$/i.test(str):/^([\da-f]{1,4}:){7}[\da-f]{1,4}$/i.test(str));
}

（5）校验是否为邮箱地址

export const isEmail = (value) {
    return /^[a-zA-Z0-9_-]+@[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)+$/.test(value);
}

（6）校验是否为中国大陆手机号

export const isTel = (value) => {
    return /^1[3,4,5,6,7,8,9][0-9]{9}$/.test(value.toString());
}

（7）校验是否包含emoji表情

export const isEmojiCharacter = (value) => {
   value = String(value);
    for (let i = 0; i < value.length; i++) {
        const hs = value.charCodeAt(i);
        if (0xd800 <= hs && hs <= 0xdbff) {
            if (value.length > 1) {
                const ls = value.charCodeAt(i + 1);
                const uc = ((hs - 0xd800) * 0x400) + (ls - 0xdc00) + 0x10000;
                if (0x1d000 <= uc && uc <= 0x1f77f) {
                    return true;
                }
            }
        } else if (value.length > 1) {
            const ls = value.charCodeAt(i + 1);
            if (ls == 0x20e3) {
                return true;
            }
        } else {
            if (0x2100 <= hs && hs <= 0x27ff) {
                return true;
            } else if (0x2B05 <= hs && hs <= 0x2b07) {
                return true;
            } else if (0x2934 <= hs && hs <= 0x2935) {
                return true;
            } else if (0x3297 <= hs && hs <= 0x3299) {
                return true;
            } else if (hs == 0xa9 || hs == 0xae || hs == 0x303d || hs == 0x3030
                    || hs == 0x2b55 || hs == 0x2b1c || hs == 0x2b1b
                    || hs == 0x2b50) {
                return true;
            }
        }
    }
   return false;
}

8. 操作URL

（1）获取URL参数列表

export const GetRequest = () => {
    let url = location.search;
    const paramsStr = /.+\?(.+)$/.exec(url)[1]; // 将 ? 后面的字符串取出来
    const paramsArr = paramsStr.split('&'); // 将字符串以 & 分割后存到数组中
    let paramsObj = {};
    // 将 params 存到对象中
    paramsArr.forEach(param => {
      if (/=/.test(param)) { // 处理有 value 的参数
        let [key, val] = param.split('='); // 分割 key 和 value
        val = decodeURIComponent(val); // 解码
        val = /^\d+$/.test(val) ? parseFloat(val) : val; // 判断是否转为数字
        if (paramsObj.hasOwnProperty(key)) { // 如果对象有 key，则添加一个值
          paramsObj[key] = [].concat(paramsObj[key], val);
        } else { // 如果对象没有这个 key，创建 key 并设置值
          paramsObj[key] = val;
        }
      } else { // 处理没有 value 的参数
        paramsObj[param] = true;
      }
    })
    return paramsObj;
};

（2）检测URL是否有效

export const getUrlState = (URL) => {
  let xmlhttp = new ActiveXObject("microsoft.xmlhttp");
  xmlhttp.Open("GET", URL, false);
  try {
    xmlhttp.Send();
  } catch (e) {
  } finally {
    let result = xmlhttp.responseText;
    if (result) {
      if (xmlhttp.Status == 200) {
        return true;
      } else {
        return false;
      }
    } else {
      return false;
    }
  }
}

（3）键值对拼接成URL参数

export const params2Url = (obj) => {
     let params = []
     for (let key in obj) {
       params.push(${key}=${obj[key]});
     }
     return encodeURIComponent(params.join('&'))
}

（4）修改URL中的参数

export const replaceParamVal => (paramName, replaceWith) {
   const oUrl = location.href.toString();
   const re = eval('/('+ paramName+'=)([^&]*)/gi');
   location.href = oUrl.replace(re,paramName+'='+replaceWith);
   return location.href;
}

（5）删除URL中指定参数

export const funcUrlDel = (name) => {
  const baseUrl = location.origin + location.pathname + "?";
  const query = location.search.substr(1);
  if (query.indexOf(name) > -1) {
    const obj = {};
    const arr = query.split("&");
    for (let i = 0; i < arr.length; i++) {
      arr[i] = arr[i].split("=");
      obj[arr[i][0]] = arr[i][1];
    }
    delete obj[name];
    return baseUrl + JSON.stringify(obj).replace(/[\"\{\}]/g,"").replace(/\:/g,"=").replace(/\,/g,"&");
  }
}

9. 设备判断

（1）判断是移动还是PC设备

export const isMobile = () => {
  if ((navigator.userAgent.match(/(iPhone|iPod|Android|ios|iOS|iPad|Backerry|WebOS|Symbian|Windows Phone|Phone)/i))) {
  return 'mobile';
  }
  return 'desktop';
}

（2）判断是否是苹果还是安卓移动设备

export const isAppleMobileDevice = () => {
  let reg = /iphone|ipod|ipad|Macintosh/i;
  return reg.test(navigator.userAgent.toLowerCase());
}

（3）判断是否是安卓移动设备

export const isAndroidMobileDevice = () => {
  return /android/i.test(navigator.userAgent.toLowerCase());
}

（4）判断是Windows还是Mac系统

export const osType = () => {
    const agent = navigator.userAgent.toLowerCase();
    const isMac = /macintosh|mac os x/i.test(navigator.userAgent);
   const isWindows = agent.indexOf("win64") >= 0 || agent.indexOf("wow64") >= 0 || agent.indexOf("win32") >= 0 || agent.indexOf("wow32") >= 0;
    if (isWindows) {
        return "windows";
    }
    if(isMac){
        return "mac";
    }
}

（5）判断是否是微信/QQ内置浏览器

export const broswer = () => {
    const ua = navigator.userAgent.toLowerCase();
    if (ua.match(/MicroMessenger/i) == "micromessenger") {
        return "weixin";
    } else if (ua.match(/QQ/i) == "qq") {
        return "QQ";
    }
    return false;
}

（6）浏览器型号和版本

export const getExplorerInfo = () => {
    let t = navigator.userAgent.toLowerCase();
    return 0 <= t.indexOf("msie") ? { //ie < 11
        type: "IE",
        version: Number(t.match(/msie ([\d]+)/)[1])
    } : !!t.match(/trident\/.+?rv:(([\d.]+))/) ? { // ie 11
        type: "IE",
        version: 11
    } : 0 <= t.indexOf("edge") ? {
        type: "Edge",
        version: Number(t.match(/edge\/([\d]+)/)[1])
    } : 0 <= t.indexOf("firefox") ? {
        type: "Firefox",
        version: Number(t.match(/firefox\/([\d]+)/)[1])
    } : 0 <= t.indexOf("chrome") ? {
        type: "Chrome",
        version: Number(t.match(/chrome\/([\d]+)/)[1])
    } : 0 <= t.indexOf("opera") ? {
        type: "Opera",
        version: Number(t.match(/opera.([\d]+)/)[1])
    } : 0 <= t.indexOf("Safari") ? {
        type: "Safari",
        version: Number(t.match(/version\/([\d]+)/)[1])
    } : {
        type: t,
        version: -1
    }
}

10. 浏览器操作

（1）滚动到页面顶部

export const scrollToTop = () => {
  const height = document.documentElement.scrollTop || document.body.scrollTop;
  if (height > 0) {
    window.requestAnimationFrame(scrollToTop);
    window.scrollTo(0, height - height / 8);
  }
}

（2）滚动到页面底部

export const scrollToBottom = () => {
  window.scrollTo(0, document.documentElement.clientHeight);  
}

（3）滚动到指定元素区域

export const smoothScroll = (element) => {
    document.querySelector(element).scrollIntoView({
        behavior: 'smooth'
    });
};

（4）获取可视窗口高度

export const getClientHeight = () => {
    let clientHeight = 0;
    if (document.body.clientHeight && document.documentElement.clientHeight) {
        clientHeight = (document.body.clientHeight < document.documentElement.clientHeight) ? document.body.clientHeight : document.documentElement.clientHeight;
    }
    else {
        clientHeight = (document.body.clientHeight > document.documentElement.clientHeight) ? document.body.clientHeight : document.documentElement.clientHeight;
    }
    return clientHeight;
}

（5）获取可视窗口宽度

export const getPageViewWidth = () => {
    return (document.compatMode == "BackCompat" ? document.body : document.documentElement).clientWidth;
}

（6）打开浏览器全屏

export const toFullScreen = () => {
    let element = document.body;
    if (element.requestFullscreen) {
      element.requestFullscreen()
    } else if (element.mozRequestFullScreen) {
      element.mozRequestFullScreen()
    } else if (element.msRequestFullscreen) {
      element.msRequestFullscreen()
    } else if (element.webkitRequestFullscreen) {
      element.webkitRequestFullScreen()
    }
}

（7）退出浏览器全屏

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()
    }
}

11. 时间操作

（1）当前时间

export const nowTime = () => {
    const now = new Date();
    const year = now.getFullYear();
    const month = now.getMonth();
    const date = now.getDate() >= 10 ? now.getDate() : ('0' + now.getDate());
    const hour = now.getHours() >= 10 ? now.getHours() : ('0' + now.getHours());
    const miu = now.getMinutes() >= 10 ? now.getMinutes() : ('0' + now.getMinutes());
    const sec = now.getSeconds() >= 10 ? now.getSeconds() : ('0' + now.getSeconds());
    return +year + "年" + (month + 1) + "月" + date + "日 " + hour + ":" + miu + ":" + sec;
}

（2）格式化时间

export const dateFormater = (formater, time) => {
    let date = time ? new Date(time) : new Date(),
        Y = date.getFullYear() + '',
        M = date.getMonth() + 1,
        D = date.getDate(),
        H = date.getHours(),
        m = date.getMinutes(),
        s = date.getSeconds();
    return formater.replace(/YYYY|yyyy/g, Y)
        .replace(/YY|yy/g, Y.substr(2, 2))
        .replace(/MM/g,(M<10 ? '0' : '') + M)
        .replace(/DD/g,(D<10 ? '0' : '') + D)
        .replace(/HH|hh/g,(H<10 ? '0' : '') + H)
        .replace(/mm/g,(m<10 ? '0' : '') + m)
        .replace(/ss/g,(s<10 ? '0' : '') + s)
}
// dateFormater('YYYY-MM-DD HH:mm:ss')
// dateFormater('YYYYMMDDHHmmss')

12. JavaScript操作

（1）阻止冒泡事件

export const stopPropagation = (e) => { 
    e = e || window.event; 
    if(e.stopPropagation) {    // W3C阻止冒泡方法 
        e.stopPropagation(); 
    } else { 
        e.cancelBubble = true; // IE阻止冒泡方法 
    } 
} 

（2）防抖函数

export const debounce = (fn, wait) => {
  let timer = null;

  return function() {
    let context = this,
        args = arguments;

    if (timer) {
      clearTimeout(timer);
      timer = null;
    }

    timer = setTimeout(() => {
      fn.apply(context, args);
    }, wait);
  };
}

（3）节流函数

export const throttle = (fn, delay) => {
  let curTime = Date.now();

  return function() {
    let context = this,
        args = arguments,
        nowTime = Date.now();

    if (nowTime - curTime >= delay) {
      curTime = Date.now();
      return fn.apply(context, args);
    }
  };
}

（4）数据类型判断

export const getType = (value) => {
  if (value === null) {
    return value + "";
  }
  // 判断数据是引用类型的情况
  if (typeof value === "object") {
    let valueClass = Object.prototype.toString.call(value),
      type = valueClass.split(" ")[1].split("");
    type.pop();
    return type.join("").toLowerCase();
  } else {
    // 判断数据是基本数据类型的情况和函数的情况
    return typeof value;
  }
}

（5）对象深拷贝

export const deepClone = (obj, hash = new WeakMap()) => {
  // 日期对象直接返回一个新的日期对象
  if (obj instanceof Date){
   return new Date(obj);
  } 
  //正则对象直接返回一个新的正则对象     
  if (obj instanceof RegExp){
   return new RegExp(obj);     
  }
  //如果循环引用,就用 weakMap 来解决
  if (hash.has(obj)){
   return hash.get(obj);
  }
  // 获取对象所有自身属性的描述
  let allDesc = Object.getOwnPropertyDescriptors(obj);
  // 遍历传入参数所有键的特性
  let cloneObj = Object.create(Object.getPrototypeOf(obj), allDesc)

  hash.set(obj, cloneObj)
  for (let key of Reflect.ownKeys(obj)) { 
    if(typeof obj[key] === 'object' && obj[key] !== null){
     cloneObj[key] = deepClone(obj[key], hash);
    } else {
     cloneObj[key] = obj[key];
    }
  }
  return cloneObj
}

以上内容来源于网络 ，作者CUGGZ，有完善与补充。