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关于前端:让你事半功倍的JS-utils工具函数

jiezi

今日分享一篇积攒和收集了很久的 JS utils 工具函数，文章代码量较多，倡议珍藏起来缓缓看，当哪一天须要用到的时候，关上你尘封已久的收藏夹，置信能让你的业务代码开发事倍功半。

会集了工夫相干，DOM 相干，URL 相干，判断相干，图片相干，缓存相干等。局部逻辑解决较为简单，如果是业务量较为简单的状况倡议要斟酌应用，但对于大部分的我的项目应该是入不敷出。接下来就进入代码局部吧～

工夫相干

工夫戳转自定义格局工夫

export const dateRegExp = (time, strText) => {const date = new Date(time)
  if (/(y+)/.test(strText)) {strText = strText.replace(RegExp.$1, (date.getFullYear() + '').substr(4 - RegExp.$1.length))
  }
  const dataType = {'M+': date.getMonth() + 1,
    'd+': date.getDate(),
    'h+': date.getHours(),
    'm+': date.getMinutes(),
    's+': date.getSeconds()}
  for (const typeKey in dataType) {if (new RegExp(`(${typeKey})`).test(strText)) {const typeValue = dataType[typeKey] + ''
      strText = strText.replace(RegExp.$1, (RegExp.$1.length === 1 ? typeValue : padLeftZero(typeValue)))
    }
  }
  return strText
}

格式化间隔当初已过来的工夫

export function formatPassTime(startTime) {var currentTime = Date.parse(new Date()),
        time = currentTime - startTime,
        day = parseInt(time / (1000 * 60 * 60 * 24)),
        hour = parseInt(time / (1000 * 60 * 60)),
        min = parseInt(time / (1000 * 60)),
        month = parseInt(day / 30),
        year = parseInt(month / 12);
    if (year) return year + "年前"
    if (month) return month + "个月前"
    if (day) return day + "天前"
    if (hour) return hour + "小时前"
    if (min) return min + "分钟前"
    else return '刚刚'
}

判断两个不同格局的日期是否为同一天

export function isSameDay(d1, d2) {if (!d2) {d2 = new Date();
    }
    var d1_year = d1.getFullYear(),
        d1_month = d1.getMonth() + 1,
        d1_date = d1.getDate();
    var d2_year = d2.getFullYear(),
        d2_month = d2.getMonth() + 1,
        d2_date = d2.getDate()

    return d1_date === d2_date && d1_month === d2_month && d1_year === d2_year;
}

判断工夫是不是明天

export function isTodayDate(time) {if (new Date(time).toDateString() === new Date().toDateString()) {return true;}
    return false;
}

URL 相干

URL 参数转对象

export function parseQueryString(url) {
    url = url ? url:window.location.search ;
    let search = url[0] === '?' ? url : url.substring(url.lastIndexOf('?')); 
    let q = {};
    search.replace(/([^?&=]+)=([^&]+)/g, (_, k, v) => q[k] = decodeURIComponent(v));
    return q;
}

获取 URL 参数

export function getQueryString(name) {const reg = new RegExp('(^|&)' + name + '=([^&]*)(&|$)', 'i')
  const r = window.location.search.substr(1).match(reg)
  if (r !== null) {return decodeURI(r[2])
  }
  return null
}

获取 URL hash 前面的参数

export getHashQueryString = (key) => {const after = window.location.href.split('?')[1]
  if (after) {const reg = new RegExp(`(^|&)${key}=([^&]*)(&|$)`)
    const r = after.match(reg)
    if (r != null) {return decodeURIComponent(r[2])
    }
    return null
  }
  return null
}

对象序列化

export function serialize(query, encode = false) {return Object.keys(query)
    .map((key) => `${key}=${encode ? encodeURIComponent(query[key]) : query[key]}`)
    .join('&')
}

判断相干

判断是否反对 Intersection

export function isSupportIntersection() {
  return (
    'IntersectionObserver' in window &&
    'IntersectionObserverEntry' in window &&
    'intersectionRatio' in window.IntersectionObserverEntry.prototype
  )
}

判断是否 IOS

export const isIOS = (() => {return /ios|iphone|ipad|ipod/.test(navigator.userAgent.toLowerCase())
})()

判断是否安卓

export const isAndroid = (() {return /android/.test(navigator.userAgent.toLowerCase())
})()

判断微信内置浏览器

export function isWeixin() {var ua = navigator.userAgent.toLowerCase();
  return (ua.match(/MicroMessenger/i) == "micromessenger")
}

判断是否反对 webp 格局 2 种形式

export function checkSupportWebp() {
  return (
    document
      .createElement('canvas')
      .toDataURL('image/webp')
      .indexOf('data:image/webp') === 0
  )
}
export function checkSupportWebp2() {var img = new Image();
  img.onload = img.onerror = (event) => {return event && event.type === "load" ? img.width == 1 : false;};
  img.src = "data:image/webp;base64,UklGRiQAAABXRUJQVlA4IBgAAAAwAQCdASoBAAEAAwA0JaQAA3AA/vuUAAA=";
}

判断浏览器是否是挪动端

export function isMobile() {
    const agent = navigator.userAgent;
    const k = ["android", "iphone", "ipod", "ipad", "windows phone", "mqqbrowser"];
    let flag = false;
    // Windows
    if (agent.indexOf("Windows NT") < 0 || (agent.indexOf("Windows NT") >= 0 && agent.indexOf("compatible; MSIE 9.0;") >= 0)) {
        // Mac PC
        if (agent.indexOf("Windows NT") < 0 && agent.indexOf("Macintosh") < 0) {for (let item of k) {if (agent.indexOf(item) >= 0) {
                    flag = true;
                    break;
                }
            }
        }
    }
    return flag;
}

文件类型判断


export function checkFileName(fileName, list) {if (typeof fileName !== 'string') return;
    let name = fileName.toLowerCase();
    return list.some(i => name.endsWith(`.${i}`) === true)
}

export function isImage(fileName) {return checkFileName(fileName, ['png', 'jpeg', 'jpg', 'png', 'bmp'])
}

export function isH5Video(fileName) {return checkFileName(fileName, ['mp4', 'webm', 'ogg'])
}
export function isPdf(fileName) {return checkFileName(fileName, ['pdf'])
}

export function isWord(fileName) {return checkFileName(fileName, ['doc', 'docx'])
}

export function isExcel(fileName) {return checkFileName(fileName, ['xlsx', 'xls'])
}

数据类型判断

export function is(subject, type) {return Object.prototype.toString.call(subject).substr(8, type.length).toLowerCase() === type}
export function isArray(subject) {return Array.isArray(subject)
}
export function isObject(subject) {return is(subject, 'object')
}

...

export function isNum(subject) {return !isNaN(subject) && is(subject, 'number')
}

DOM 相干

查问元素是否存在某个 class

export function hasClass(el, className) {let reg = new RegExp('(^|\\s)' + className + '(\\s|$)');
  return reg.test(el.className);
}

给某个元素增加 class

export function addClass(el, className) {if (hasClass(el, className)) {return;}
  let curClass = el.className.split(' ');
  curClass.push(className);
  el.className = curClass.join(' ');
}

删除某个元素的 class

export function removeClass(el, className) {if (!hasClass(el, className)) {return;}

  let reg = new RegExp('(^|\\s)' + className + '(\\s|$)', 'g');
  el.className = el.className.replace(reg, ' ');
}

获取页面滚动间隔

export function getScrollTop() {
  let e = 0
  return (
    document.documentElement && document.documentElement.scrollTop
      ? (e = document.documentElement.scrollTop)
      : document.body && (e = document.body.scrollTop),
    e
  )
}

滚动到某个地位回调

export function distanceScroll(distance, callback) {
  const scrollTop = document.body.scrollTop || document.documentElement.scrollTop
  const docHeight = document.body.clientHeight
  const screenHeight = window.screen.availHeight
  const differ = scrollTop > docHeight - screenHeight - distance
  if (differ) {callback && callback()
  }
}

拨打电话

export const callPhone = (phone) => {const aElement = document.createElement('a')
  aElement.setAttribute('href', `tel:${phone}`)
  document.body.appendChild(aElement)
  aElement.click()
  document.body.removeChild(aElement)
}

复制文本

export function copy(value, callback) {if (!document.queryCommandSupported('copy')) {callback('暂不反对复制')
    return
  }
  const textarea = document.createElement('textarea')
  textarea.value = value
  textarea.readOnly = Boolean('readOnly')
  document.body.appendChild(textarea)
  textarea.select()
  textarea.setSelectionRange(0, value.length)
  document.execCommand('copy')
  textarea.remove()
  callback('复制胜利')
}

动静加载第三方 js

export function asyncLoadScript(url) {return new Promise(function (resolve, reject) {const tag = document.getElementsByTagName('script')
    for (const i of tag) {if (i.src === url) {resolve()
        return
      }
    }
    const script = document.createElement('script')
    script.type = 'text/javascript'
    script.src = url
    script.onerror = reject
    document.body.appendChild(script)
    script.onload = () => {resolve()
    }
  })
}

解决 requestAnimationFrame 的兼容问题

export function requestAnimationFrame() {return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || function (callback) {return setTimeout(callback, (callback.interval ||（100 / 60) / 2);
  };
}()

动态创建 form 表单导出数据(POST)

const postExport = (url, data = {}) => {const form = document.createElement("form");
  form.style.display = "none";
  form.action = `${Config.baseURL}${url}`;
  form.method = "post";
  document.body.appendChild(form);
  // 动态创建 input 并给 value 赋值
  for (const key in data) {const input = document.createElement("input");
    input.type = "hidden";
    input.name = key;
    input.value = data[key];
    form.appendChild(input);
  }
  form.submit();
  form.remove();}

图片相干

base64 转 Buffer

export function dataURItoBuffer(dataURI) {var byteString = atob(dataURI.split(',')[1]);
  var buffer = new ArrayBuffer(byteString.length);
  var view = new Uint8Array(buffer);

  for (var i = 0; i < byteString.length; i++) {view[i] = byteString.charCodeAt(i);
  }

  return buffer;
}

base64 转 Blob

export function dataURItoBlob(dataURI) {var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
  var buffer = dataURItoBuffer(dataURI);
  return new Blob([buffer], {type: mimeString});
}

调整拍照图片方向

export function orientationHelper(canvas, ctx, orientation) {
  var w = canvas.width;
  var h = canvas.height;

  if (orientation > 4) {
    canvas.width = h;
    canvas.height = w;
  }

  switch (orientation) {
    case 2:
      ctx.translate(w, 0);
      ctx.scale(-1, 1);
      break;

    case 3:
      ctx.translate(w, h);
      ctx.rotate(Math.PI);
      break;

    case 4:
      ctx.translate(0, h);
      ctx.scale(1, -1);
      break;

    case 5:
      ctx.rotate(0.5 * Math.PI);
      ctx.scale(1, -1);
      break;

    case 6:
      ctx.rotate(0.5 * Math.PI);
      ctx.translate(0, -h);
      break;

    case 7:
      ctx.rotate(0.5 * Math.PI);
      ctx.translate(w, -h);
      ctx.scale(-1, 1);
      break;

    case 8:
      ctx.rotate(-0.5 * Math.PI);
      ctx.translate(-w, 0);
      break;
  }
}

缓存相干

获取指定 Cookie 值

export const getCookie = (k) => {const res = RegExp('(^|;)' + encodeURIComponent(k) + '=([^;]*)').exec(document.cookie)
  return res && res[2]
}

设置 Cookie 值

export function setCookie(name, value, expriesDays, encode = false) {
  var Days = expriesDays || 10
  var exp = new Date()
  exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000)
  const val = encode ? escape(value) : value
  document.cookie = name + '=' + val + ';domain=zhuanzhuan.com;path=/;expires=' + exp.toUTCString()}

简易版 Storage 操作，sessionStorage 及 localStorage 相似

const prefix = '_XXX_'
export function getStorage(key) {const content = sessionStorage.getItem(`${prefix}${key}`)
  if (content) {
    try {const params = JSON.parse(content)
      const expires = params.expires
      // 未设置过期 及 未过期
      if (!expires || (expires && Date.now() <= expires)) {return params.data}
    } catch (e) {console.log(e)
    }
  }
}

export function setStorage(key, data = {}, expires) {
  try {const params = { data}
    if (expires) {params.expires = expires}
    sessionStorage.setItem(`${prefix}${key}`, JSON.stringify(params))
  } catch (e) {console.log(e)
  }
}

数字相干

数字四舍五入，保留 n 位小数

export function round(number, n) {n = n ? parseInt(n) : 0
    if (n <= 0) return Math.round(number)
    number = Math.round(number * Math.pow(10, n)) / Math.pow(10, n)
    return number
}

数字每千位加逗号

export function toThousands(num) {return num && num.toString()
    .replace(/\d+/, function(s){return s.replace(/(\d)(?=(\d{3})+$)/g, '$1,')
     })
}

随机数

export function random(min, max) {return Math.floor(Math.random() * (max - min + 1) + min)
}

字符串相干

手机号码两头 4 位暗藏星号

export function hideMobile(mobile) {return mobile.replace(/^(\d{3})\d{4}(\d{4})$/, "$1****$2")
}

检测明码强度 1：明码弱 2：明码中等 3：明码强 4：明码很强

export function checkPassWord(str) {
    let level = 0;
    if (str.length < 6) {return level};
    if (/[0-9]/.test(str)) {level++};
    if (/[a-z]/.test(str)) {level++};
    if (/[A-Z]/.test(str)) {level++};
    if(/\W/.test(str)){level++}
    return level
}

随机产生某个色彩

export function randomColor() {return `rgb(${this.random(0, 255)}, ${this.random(0, 255)}, ${this.random(0, 255)})`
}

字符串替换全副

export function replaceAll(s0, s1, s2){return s0.replace(new RegExp(s1, "gm"), s2);
}

版本号比拟

传入两个版本号，格局如：4.3.2，返回后果，小于 -1，等于 0，大于 1。

export function compareVersion(v1, v2) {var s1 = v1.split(".").map(v => parseInt(v));
  var s2 = v2.split(".").map(v => parseInt(v));

  var len1 = s1.length, len2 = s2.length, commonLen = Math.min(len1, len2);
  for (var i = 0; i < commonLen; ++i) {if (seq1[i] != seq2[i])
      return seq1[i]<seq2[i] ? -1 : 1;
  }

  return len1 === len2 ? 0 : (len1 < len2 ? -1 : 1);
}

对象转 url 字符串供导出接口 (GET) 应用

const objectToQueryString = (paramObj) => {const tmpArray = []
  // 特殊字符本义
  const filter = (str) => {
    str += '' // 隐式转换
    str = str.replace(/%/g, '%25')
    str = str.replace(/\+/g, '%2B')
    str = str.replace(/ /g, '%20')
    str = str.replace(/\//g, '%2F')
    str = str.replace(/\?/g, '%3F')
    str = str.replace(/&/g, '%26')
    str = str.replace(/\=/g, '%3D')
    str = str.replace(/#/g, '%23')
    return str
  }
  for (const attr in paramObj) {tmpArray.push(`${attr}=${filter(paramObj[attr])}`)
  }
  return tmpArray.join('&')
}

其余

函数防抖

export function debounce(fn, delay) {
  delay = delay || 1000;
  let timer = null;
  return function () {
    let context = this;
    let arg = arguments;
    if (timer) {clearTimeout(timer);
    }
    timer = setTimeout(() => {fn.apply(context, arg);
    }, delay);
  };
}

节流函数

export function throttle(fn, delay = 300) {
  let timer = null;
  return function () {
    let context = this;
    let args = arguments;
    if (!timer) {timer = setTimeout(function () {fn.apply(context, args);
        clearTimeout(timer);
      }, delay);
    }
  };
}

最初

除开本文所示的场景，也还有很多没有列举到的状况，如果你有认为很不错的工具函数，欢送留言交换～

专一前端开发，分享前端相干技术干货，公众号：南城大前端（ID: nanchengfe）

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