1、isStatic:检测数据是不是除了symbol外的原始数据 1 2 3 4 5 6 7 8 9 function isStatic (value ) { return ( typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean' || typeof value === 'undefined' || value === null ) }
2、isPrimitive:检测数据是不是原始数据 1 2 3 function isPrimitive (value ) { return isStatic(value) || typeof value === 'symbol' }
3、isObject:判断数据是不是引用类型的数据 (例如: arrays, functions, objects, regexes, new Number(0),以及 new String(‘’)) 1 2 3 4 function isObject (value ) { let type = typeof value; return value != null && (type == 'object' || type == 'function' ); }
4、isObjectLike:检查 value 是否是 类对象。 如果一个值是类对象,那么它不应该是 null,而且 typeof 后的结果是 “object” 1 2 3 function isObjectLike (value ) { return value != null && typeof value == 'object' ; }
5、getRawType:获取数据类型,返回结果为 Number、String、Object、Array等 1 2 3 4 function getRawType (value ) { return Object .prototype.toString.call(value).slice(8 , -1 ) }
6、isPlainObject:判断数据是不是Object类型的数据 1 2 3 function isPlainObject (obj ) { return Object .prototype.toString.call(obj) === '[object Object]' }
7、isArray:判断数据是不是数组类型的数据 1 2 3 4 5 function isArray (arr ) { return Object .prototype.toString.call(arr) === '[object Array]' } 将isArray挂载到Array 上 Array .isArray = Array .isArray || isArray;
8、isRegExp:判断数据是不是正则对象 1 2 3 function isRegExp (value ) { return Object .prototype.toString.call(value) === '[object RegExp]' }
9、isDate:判断数据是不是时间对象 1 2 3 function isDate (value ) { return Object .prototype.toString.call(value) === '[object Date]' }
10、isNative:判断 value 是不是浏览器内置函数 内置函数toString后的主体代码块为 [native code] ,而非内置函数则为相关代码,所以非内置函数可以进行拷贝(toString后掐头去尾再由Function转)
1 2 3 function isNative (value ) { return typeof value === 'function' && /native code/ .test(value.toString()) }
11、isFunction:检查 value 是不是函数 1 2 3 function isFunction (value ) { return Object .prototype.toString.call(value) === '[object Function]' }
12、isLength:检查 value 是否为有效的类数组长度 1 2 3 function isLength (value ) { return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= Number .MAX_SAFE_INTEGER; }
13、isArrayLike:检查 value 是否是类数组 如果一个值被认为是类数组,那么它不是一个函数,并且value.length是个整数,大于等于 0,小于或等于 Number.MAX_SAFE_INTEGER。这里字符串也将被当作类数组。
1 2 3 function isArrayLike (value ) { return value != null && isLength(value.length) && !isFunction(value); }
14、isEmpty:检查 value 是否为空 如果是null,直接返回true;如果是类数组,判断数据长度;如果是Object对象,判断是否具有属性;如果是其他数据,直接返回false(也可改为返回true)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 function isEmpty (value ) { if (value == null ) { return true ; } if (isArrayLike(value)) { return !value.length; }else if (isPlainObject(value)){ for (let key in value) { if (hasOwnProperty.call(value, key)) { return false ; } } } return false ; }
15、cached:记忆函数:缓存函数的运算结果 1 2 3 4 5 6 7 function cached (fn ) { let cache = Object .create(null ); return function cachedFn (str ) { let hit = cache[str]; return hit || (cache[str] = fn(str)) } }
16、camelize:横线转驼峰命名 1 2 3 4 5 6 7 8 9 let camelizeRE = /-(\w)/g ;function camelize (str ) { return str.replace(camelizeRE, function (_, c ) { return c ? c.toUpperCase() : '' ; }) } let _camelize = cached(camelize)
17、hyphenate:驼峰命名转横线命名:拆分字符串,使用 - 相连,并且转换为小写 1 2 3 4 5 6 7 let hyphenateRE = /\B([A-Z])/g ;function hyphenate (str ) { return str.replace(hyphenateRE, '-$1' ).toLowerCase() } let _hyphenate = cached(hyphenate);
18、capitalize:字符串首位大写 1 2 3 4 5 6 function capitalize (str ) { return str.charAt(0 ).toUpperCase() + str.slice(1 ) } let _capitalize = cached(capitalize)
19、extend:将属性混合到目标对象中 1 2 3 4 5 6 function extend (to, _from ) { for (let key in _from) { to[key] = _from[key]; } return to }
20、Object.assign:对象属性复制,浅拷贝 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Object .assign = Object .assign || function ( ) { if (arguments .length == 0 ) throw new TypeError ('Cannot convert undefined or null to object' ); let target = arguments [0 ], args = Array .prototype.slice.call(arguments , 1 ), key args.forEach(function (item ) { for (key in item){ item.hasOwnProperty(key) && ( target[key] = item[key] ) } }) return target } let clone = Object .assign({}, target)let clone = JSON .parse( JSON .stringify(target) )
21、clone:克隆数据,可深度克隆 这里列出了原始类型,时间、正则、错误、数组、对象的克隆规则,其他的可自行补充
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 function clone (value, deep ) { if (isPrimitive(value)){ return value } if (isArrayLike(value)) { value = Array .prototype.slice.call(value) return value.map(item => deep ? clone(item, deep) : item) }else if (isPlainObject(value)){ let target = {}, key; for (key in value) { value.hasOwnProperty(key) && ( target[key] = deep ? clone(value[key], deep) : value[key] ) } } let type = getRawType(value) switch (type){ case 'Date' : case 'RegExp' : case 'Error' : value = new window [type](value); break ; } return value }
22、识别各种浏览器及平台 1 2 3 4 5 6 7 8 9 10 11 12 13 let inBrowser = typeof window !== 'undefined' ;let inWeex = typeof WXEnvironment !== 'undefined' && !!WXEnvironment.platform;let weexPlatform = inWeex && WXEnvironment.platform.toLowerCase();let UA = inBrowser && window .navigator.userAgent.toLowerCase();let isIE = UA && /msie|trident/ .test(UA);let isIE9 = UA && UA.indexOf('msie 9.0' ) > 0 ;let isEdge = UA && UA.indexOf('edge/' ) > 0 ;let isAndroid = (UA && UA.indexOf('android' ) > 0 ) || (weexPlatform === 'android' );let isIOS = (UA && /iphone|ipad|ipod|ios/ .test(UA)) || (weexPlatform === 'ios' );let isChrome = UA && /chrome\/\d+/ .test(UA) && !isEdge;
23、getExplorerInfo:获取浏览器信息 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 function getExplorerInfo ( ) { let t = navigator.userAgent.toLowerCase(); return 0 <= t.indexOf("msie" ) ? { type: "IE" , version: Number (t.match(/msie ([\d]+)/ )[1 ]) } : !!t.match(/trident\/.+?rv:(([\d.]+))/ ) ? { 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 } }
24、isPCBroswer:检测是否为PC端浏览器模式 1 2 3 4 5 6 7 8 9 10 11 12 function isPCBroswer ( ) { let e = navigator.userAgent.toLowerCase() , t = "ipad" == e.match(/ipad/i ) , i = "iphone" == e.match(/iphone/i ) , r = "midp" == e.match(/midp/i ) , n = "rv:1.2.3.4" == e.match(/rv:1.2.3.4/i ) , a = "ucweb" == e.match(/ucweb/i ) , o = "android" == e.match(/android/i ) , s = "windows ce" == e.match(/windows ce/i ) , l = "windows mobile" == e.match(/windows mobile/i ); return !(t || i || r || n || a || o || s || l) }
25、unique:数组去重,返回一个新数组 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 function unique (arr ) { if (!isArrayLink(arr)){ return arr } let result = [] let objarr = [] let obj = Object .create(null ) arr.forEach(item => { if (isStatic(item)){ let key = item + '_' + getRawType(item); if (!obj[key]){ obj[key] = true result.push(item) } }else { if (!objarr.includes(item)){ objarr.push(item) result.push(item) } } }) return resulte }
26、Set简单实现 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 window .Set = window .Set || (function ( ) { function Set (arr ) { this .items = arr ? unique(arr) : []; this .size = this .items.length; } Set .prototype = { add: function (value ) { if (!this .has(value)) { this .items.push(value); this .size++; } return this ; }, clear: function ( ) { this .items = [] this .size = 0 }, delete : function (value ) { return this .items.some((v, i ) => { if (v === value){ this .items.splice(i,1 ) return true } return false }) }, has: function (value ) { return this .items.some(v => v === value) }, values: function ( ) { return this .items }, } return Set ; }());
27、repeat:生成一个重复的字符串,有n个str组成,可修改为填充为数组等 1 2 3 4 5 6 7 8 9 10 11 12 13 14 function repeat (str, n ) { let res = '' ; while (n) { if (n % 2 === 1 ) { res += str; } if (n > 1 ) { str += str; } n >>= 1 ; } return res };
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 function dateFormater (formater, t ) { let date = t ? new Date (t) : 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) }
from的格式应对应str的位置
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 function dateStrForma (str, from, to ) { str += '' let Y = '' if (~(Y = from .indexOf('YYYY' ))){ Y = str.substr(Y, 4 ) to = to.replace(/YYYY|yyyy/g ,Y) }else if (~(Y = from .indexOf('YY' ))){ Y = str.substr(Y, 2 ) to = to.replace(/YY|yy/g ,Y) } let k,i ['M' ,'D' ,'H' ,'h' ,'m' ,'s' ].forEach(s => { i = from .indexOf(s+s) k = ~i ? str.substr(i, 2 ) : '' to = to.replace(s+s, k) }) return to }
30、getPropByPath:根据字符串路径获取对象属性 : ‘obj[0].count’ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 function getPropByPath (obj, path, strict ) { let tempObj = obj; path = path.replace(/\[(\w+)\]/g , '.$1' ); path = path.replace(/^\./ , '' ); let keyArr = path.split('.' ); let i = 0 ; for (let len = keyArr.length; i < len - 1 ; ++i) { if (!tempObj && !strict) break ; let key = keyArr[i]; if (key in tempObj) { tempObj = tempObj[key]; } else { if (strict) { throw new Error ('please transfer a valid prop path to form item!' ); } break ; } } return { o: tempObj, k: keyArr[i], v: tempObj ? tempObj[keyArr[i]] : null }; };
31、GetUrlParam:获取Url参数,返回一个对象 1 2 3 4 5 6 7 8 9 10 11 12 13 14 function GetUrlParam ( ) { let url = document .location.toString(); let arrObj = url.split("?" ); let params = Object .create(null ) if (arrObj.length > 1 ){ arrObj = arrObj[1 ].split("&" ); arrObj.forEach(item => { item = item.split("=" ); params[item[0 ]] = item[1 ] }) } return params; }
32、downloadFile:base64数据导出文件,文件下载 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 function downloadFile (filename, data ) { let DownloadLink = document .createElement('a' ); if ( DownloadLink ){ document .body.appendChild(DownloadLink); DownloadLink.style = 'display: none' ; DownloadLink.download = filename; DownloadLink.href = data; if ( document .createEvent ){ let DownloadEvt = document .createEvent('MouseEvents' ); DownloadEvt.initEvent('click' , true , false ); DownloadLink.dispatchEvent(DownloadEvt); } else if ( document .createEventObject ) DownloadLink.fireEvent('onclick' ); else if (typeof DownloadLink.onclick == 'function' ) DownloadLink.onclick(); document .body.removeChild(DownloadLink); } }
33、toFullScreen:全屏 1 2 3 4 5 6 7 8 9 10 11 12 function toFullScreen ( ) { let elem = document .body; elem.webkitRequestFullScreen ? elem.webkitRequestFullScreen() : elem.mozRequestFullScreen ? elem.mozRequestFullScreen() : elem.msRequestFullscreen ? elem.msRequestFullscreen() : elem.requestFullScreen ? elem.requestFullScreen() : alert("浏览器不支持全屏" ); }
34、exitFullscreen:退出全屏 1 2 3 4 5 6 7 8 9 10 11 12 13 14 function exitFullscreen ( ) { let elem = parent.document; elem.webkitCancelFullScreen ? elem.webkitCancelFullScreen() : elem.mozCancelFullScreen ? elem.mozCancelFullScreen() : elem.cancelFullScreen ? elem.cancelFullScreen() : elem.msExitFullscreen ? elem.msExitFullscreen() : elem.exitFullscreen ? elem.exitFullscreen() : alert("切换失败,可尝试Esc退出" ); }
35、requestAnimationFrame:window动画 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 window .requestAnimationFrame = window .requestAnimationFrame || window .webkitRequestAnimationFrame || window .mozRequestAnimationFrame || window .msRequestAnimationFrame || window .oRequestAnimationFrame || function (callback ) { window .setTimeout(callback, 1000 / 60 ); }; window .cancelAnimationFrame = window .cancelAnimationFrame || Window.webkitCancelAnimationFrame || window .mozCancelAnimationFrame || window .msCancelAnimationFrame || window .oCancelAnimationFrame || function (id ) { window .clearTimeout(id); }
36、_isNaN:检查数据是否是非数字值 原生的isNaN会把参数转换成数字(valueof),而null、true、false以及长度小于等于1的数组(元素为非NaN数据)会被转换成数字,这不是我想要的。Symbol类型的数据不具有valueof接口,所以isNaN会抛出错误,这里放在后面,可避免错误
1 2 3 function _isNaN (v ) { return !(typeof v === 'string' || typeof v === 'number' ) || isNaN (v) }
37、max:求取数组中非NaN数据中的最大值 1 2 3 4 5 function max (arr ) { arr = arr.filter(item => !_isNaN(item)) return arr.length ? Math .max.apply(null , arr) : undefined }
38、min:求取数组中非NaN数据中的最小值 1 2 3 4 5 function min (arr ) { arr = arr.filter(item => !_isNaN(item)) return arr.length ? Math .min.apply(null , arr) : undefined }
39、random:返回一个lower - upper之间的随机数 lower、upper无论正负与大小,但必须是非NaN的数据
1 2 3 4 5 6 7 8 function random (lower, upper ) { lower = +lower || 0 upper = +upper || 0 return Math .random() * (upper - lower) + lower; }
40、Object.keys:返回一个由一个给定对象的自身可枚举属性组成的数组 1 2 3 4 5 6 7 8 9 10 11 12 Object .keys = Object .keys || function keys (object ) { if (object === null || object === undefined ){ throw new TypeError ('Cannot convert undefined or null to object' ); } let result = [] if (isArrayLike(object) || isPlainObject(object)){ for (let key in object) { object.hasOwnProperty(key) && ( result.push(key) ) } } return result }
41、Object.values:返回一个给定对象自身的所有可枚举属性值的数组 1 2 3 4 5 6 7 8 9 10 11 12 Object .values = Object .values || function values (object ) { if (object === null || object === undefined ){ throw new TypeError ('Cannot convert undefined or null to object' ); } let result = [] if (isArrayLike(object) || isPlainObject(object)){ for (let key in object) { object.hasOwnProperty(key) && ( result.push(object[key]) ) } } return result }
42、arr.fill:使用 value 值来填充 array,从start位置开始, 到end位置结束(但不包含end位置),返回原数组 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Array .prototype.fill = Array .prototype.fill || function fill (value, start, end ) { let ctx = this let length = ctx.length; start = parseInt (start) if (isNaN (start)){ start = 0 }else if (start < 0 ) { start = -start > length ? 0 : (length + start); } end = parseInt (end) if (isNaN (end) || end > length){ end = length }else if (end < 0 ) { end += length; } while (start < end) { ctx[start++] = value; } return ctx; }
43、arr.includes:用来判断一个数组是否包含一个指定的值,如果是返回 true,否则false,可指定开始查询的位置 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Array .prototype.includes = Array .prototype.includes || function includes (value, start ) { let ctx = this let length = ctx.length; start = parseInt (start) if (isNaN (start)){ start = 0 }else if (start < 0 ) { start = -start > length ? 0 : (length + start); } let index = ctx.indexOf(value) return index >= start; }
44、arr.find:返回数组中通过测试(函数fn内判断)的第一个元素的值 1 2 3 4 5 6 7 8 9 10 Array .prototype.find = Array .prototype.find || function find (fn, ctx ) { ctx = ctx || this let result; ctx.some((value, index, arr ), thisValue ) => { return fn(value, index, arr) ? (result = value, true ) : false }) return result }
45、arr.findIndex :返回数组中通过测试(函数fn内判断)的第一个元素的下标 1 2 3 4 5 6 7 8 9 10 Array .prototype.findIndex = Array .prototype.findIndex || function findIndex (fn, ctx ) { ctx = ctx || this let result; ctx.some((value, index, arr ), thisValue ) => { return fn(value, index, arr) ? (result = index, true ) : false }) return result }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 window .onload = function ( ) { setTimeout(function ( ) { let t = performance.timing console .log('DNS查询耗时 :' + (t.domainLookupEnd - t.domainLookupStart).toFixed(0 )) console .log('TCP链接耗时 :' + (t.connectEnd - t.connectStart).toFixed(0 )) console .log('request请求耗时 :' + (t.responseEnd - t.responseStart).toFixed(0 )) console .log('解析dom树耗时 :' + (t.domComplete - t.domInteractive).toFixed(0 )) console .log('白屏时间 :' + (t.responseStart - t.navigationStart).toFixed(0 )) console .log('domready时间 :' + (t.domContentLoadedEventEnd - t.navigationStart).toFixed(0 )) console .log('onload时间 :' + (t.loadEventEnd - t.navigationStart).toFixed(0 )) if (t = performance.memory){ console .log('js内存使用占比 :' + (t.usedJSHeapSize / t.totalJSHeapSize * 100 ).toFixed(2 ) + '%' ) } }) }
47、禁止某些键盘事件 1 2 3 4 5 6 7 8 9 10 11 document .addEventListener('keydown' , function (event ) { return !( 112 == event.keyCode || 123 == event.keyCode || event.ctrlKey && 82 == event.keyCode || event.ctrlKey && 78 == event.keyCode || event.shiftKey && 121 == event.keyCode || event.altKey && 115 == event.keyCode || "A" == event.srcElement.tagName && event.shiftKey ) || (event.returnValue = false ) });
48、禁止右键、选择、复制 1 2 3 4 5 ['contextmenu' , 'selectstart' , 'copy' ].forEach(function (ev ) { document .addEventListener(ev, function (event ) { return event.returnValue = false }) });
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