常用Javascript函数与原型功能收藏(必看篇)

 // 重复字符串 String.prototype.repeat = function(n) { return new Array(n+1).join(this); } // 替换全部 String.prototype.replaceAll = function(str1, str2) { return this.replace(new RegExp(str1, "gm"), str2); } // 清除空格 String.prototype.trim = function() { return this.replace(/^\s*(.*?)\s+$/, "$1"); } // 计算数组中的最大值 Array.prototype.max = function() { return Math.max.apply({}, this); } // 计算数组中的最小值 Array.prototype.min = function() { return Math.min.apply({}, this); } // 复制数组 Array.prototype.copy = function() { return [].concat(this); }; // 去除数组中指定元素，只能去除一个，如果想多个，之前先用unique处理 Array.prototype.remove = function(value){ for (var i = 0, len = this.length; i .*?<\/script>/ig, ''); } // 检验URL链接是否有效 function getUrlState(url) { var xmlhttp = new ActiveXObject("microsoft.xmlhttp"); xmlhttp.open("GET", url, false); try { xmlhttp.send(); } catch(e) { } finally { var result = xmlhttp.responseText; if (result) { if (xmlhttp.status == 200) { return true; } else { return false; } } else { return false; } } } // 格式化CSS代码 function formatCss(str){ str = str.replace(/\s*([\{\}\:\;\,])\s*/g, "$1"); str = str.replace(/;\s*;/g, ";"); //清除连续分号 str = str.replace(/\,[\s\.\#\d]*{/g, "{"); str = str.replace(/([^\s])\{([^\s])/g, "$1 {\n\t$2"); str = str.replace(/([^\s])\}([^\n]*)/g, "$1\n}\n$2"); str = str.replace(/([^\s]);([^\s\}])/g, "$1;\n\t$2"); return str; } // 压缩CSS代码 function compressCss (str) { str = str.replace(/\/\*(.|\n)*?\*\//g, "");    //删除注释 str = str.replace(/\s*([\{\}\:\;\,])\s*/g, "$1"); str = str.replace(/\,[\s\.\#\d]*\{/g, "{");    //容错处理 str = str.replace(/;\s*;/g, ";");         //清除连续分号 str = str.match(/^\s*(\S+(\s+\S+)*)\s*$/);    //去掉首尾空白 return (str == null) ? "" : s[1]; } // getElementsByClassName function getElementsByClassName(name, context) { var context = context || document; if (context.getElementsByClassName) { return context.getElementsByClassName(name); } var nodes = context.getElementsByTagName("*"), nodesLength = nodes.length, ret = []; for (var i = 0; i 47 && iKey <58)   {return true;} /*数字*/ if (iKey>64 && iKey <91)   {return true;} /*字母*/ if (iKey>95 && iKey <108)  {return true;} /*数字键盘1*/ if (iKey>108 && iKey <112)  {return true;} /*数字键盘2*/ if (iKey>185 && iKey <193)  {return true;} /*符号1*/ if (iKey>218 && iKey <223)  {return true;} /*符号2*/ return false; } // 获得URL中GET参数值 function getParams() { var queryStr = window.location.href.split("?"); var params = []; if (queryStr[1]) { var gets = queryStr[1].split("&"); for (var i = 0; i /g, ">"); s = s.replace(/\'/g, "'"); s = s.replace(/\"/g, "&qout;"); return s; } // HTML还原 function htmlDecode(str) { var s = ""; if (str.length == 0) return ""; s = str.replace(/&/g, "&"); s = s.replace(//g, ">"); s = s.replace(/'/g, "\'"); s = s.replace(/&qout;/g, "\""); return s; } // 克隆 function clone(obj) { var ret; switch (typeof obj) { case 'undefined': break; case 'string': ret = obj + ''; break; case 'number': ret = obj - 0; break; case 'boolean': ret = obj; break; case 'object': if (obj === null) { ret = null; } else { if (obj instanceof Array) { ret = []; for (var i = 0, len = obj.length; i  24 || time[3] > 60 || time[4] > 60) { return false } return true; } // 检测变量类型是否为日期格式 function checkDate(str) { var date = str.match(/^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2})$/); if (date == null) { return false; } var d = new Date(r[1], r[3]-1, r[4]); return (d.getFullYear() == r[1] && (d.getMonth()+1) == r[3] && d.getDate() == r[4]); } // 检测变量是否为长日期格式 function checkDateTime(str) { var reg = /^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2}) (\d{1,2}):(\d{1,2}):(\d{1,2})$/; var dt = str.match(reg); if (dt == null) { return false; } var d = new Date(dt[1], dt[3]-1, dt[4], dt[5], dt[6], dt[7]); return (d.getFullYear() == dt[1] && (d.getMonth()+1) == dt[3] && d.getDate() == dt[4] && d.getHours() == dt[5] && d.getMinutes() == dt[6] && d.getSeconds() == dt[7]); } // 检测变量是否为未定义 function isUndefined(val) { return typeof val === 'undefined'; } // 检测变量是否为定义 function isDefined(val) { return typeof val !== 'undefined'; } // 检测变量类型是否为对象 function isObject(val) { return val !== null && typeof val === 'object'; } // 检测变量类型是否为空对象 function isBlankObject(val) { return val !== null && typeof val === 'object' && !Object.getPrototypeOf(val); } // 检测变量类型是否为字符串 function isString(val) { return typeof val === 'string'; } // 检测变量类型是否为数字 function isNumber(val) { return typeof val === 'number'; } // 检测变量类型是否为日期 function isDate(val) { return toString.call(val) === '[object Date]'; } // 检测变量类型是否为函数 function isFunction(val) { return typeof val === 'function'; } // 检测变量类型是否为正则表达式 function isRegExp(val) { return toString.call(val) === '[object RegExp]'; } // 检测变量是否window窗体对象 function isWindow(obj) { return obj && obj.window === obj; } // 检测变量类型是否为布尔 function isBoolean(val) { return typeof val === 'boolean'; } // 检测变量类型是否为文件对象 function isFile(obj) { return toString.call(obj) === '[object File]'; } // 检测变量类型是否为表单对象 function isFormData(obj) { return toString.call(obj) === '[object FormData]'; } // 检测变量类型是否为二进制对象 function isBlob(obj) { return toString.call(obj) === '[object Blob]'; } // 转全角字符 function toDBC(str) { var result = ""; var len = str.length; for (var i = 0; i = 0x0021 && code <= 0x007E) ? (code + 65248) : code; //处理空格 code = (code == 0x0020) ? 0x03000 : code; result += String.fromCharCode(code); } return result; } // 转半角字符 function toSBC(str) { var result = ""; var len = str.length; for (var i = 0; i = 0xFF01 && code <= 0xFF5E) ? (code - 65248) : code; //处理空格 code = (code == 0x03000) ? 0x0020 : code; result += String.fromCharCode(code); } return result; } // 全角半角转换 // angle: 0全到半，1半到全，其他不转化 function chgAngle(str, angle) { if (typeof str != "string" || str.length <= 0 || !(angle === 0 || angle == 1)) { return str; } var i, len, ret = [], code; if (angle) { /*半->全*/ for (i = 0, len = str.length; i 半*/ for (i = 0, len = str.length; i  65280 && code <65375) { code -= 65248; } ret.push(String.fromCharCode(code)); } } return ret.join(""); } // 数据的本地化存储 function makeWebStorage() { //IE用userdata实现，w3c浏览器本身支持 if (("localStorage" in window)) { var store = { set  : function(key, value) {localStorage.setItem(key, value)}, get  : function(key)    {return localStorage.getItem(key)}, remove : function(key)    {return localStorage.removeItem(key)} } } else { var store = { userData : null, name   : location.hostname, init   : function () { if (!store.userData) { try { store.userData = document.createElement('INPUT'); store.userData.type = "hidden"; store.userData.style.display = "none"; store.userData.addBehavior("#default#userData"); document.body.appendChild(store.userData); var expires = new Date(); expires.setDate(expires.getDate() + 365); store.userData.expires = expires.toUTCString(); } catch (e) { return false; } } return true; }, setItem : function(key, value) { if (store.init()) { store.userData.load(store.name); store.userData.setAttribute(key, value); store.userData.save(store.name); } }, getItem : function(key) { if (store.init()) { store.userData.load(store.name); return store.userData.getAttribute(key); } }, remove : function(key) { if (store.init()) { store.userData.load(store.name); store.userData.removeAttribute(key); store.userData.save(store.name); } } }; } window.webStorage = store; } function makeSessionStorage() { if (("sessionStorage" in window)) { var store = { set  : function(key, value) {window.sessionStorage.setItem(key, value)}, get  : function(key)    {return window.sessionStorage.getItem(key)}, remove : function(key)    {return window.sessionStorage.removeItem(key)} } } else { var store = { set  : function(key, value) {}, get  : function(key)    {}, remove : function(key)    {} } } window.sessStorage = store; }