JS擴(kuò)展方法與C#的擴(kuò)展方法非常相似，也是可以鏈?zhǔn)秸{(diào)用的，也是通過對(duì)某個(gè)類的擴(kuò)展寫法來(lái)實(shí)現(xiàn)。這個(gè)東西非常好用，如果將預(yù)先寫好的方法放到一個(gè)js里面引用的話，那么后面寫js將非常有趣。
下面給出一個(gè)例子：
<head>
<title>測(cè)試JS擴(kuò)展方法</title>
<script type="text/javascript">
// 合并多個(gè)空白為一個(gè)空白
String.prototype.ResetBlank = function() { //對(duì)字符串?dāng)U展
var regEx = /\s+/g;
return this.replace(regEx, ' ');
};
window.onload = function()
{
var str = "你 在他想還好嗎?";
alert(str);
str = str.ResetBlank(); //這樣就能夠調(diào)用了，跟C#的很像吧!
alert(str);
}
</script>
</head>
好像只是告訴自己有這樣一個(gè)東西而已；
下面給出找到的一個(gè)非常不錯(cuò)的js擴(kuò)展：
// 清除兩邊的空格
String.prototype.trim = function() {
return this.replace(/(^\s*)|(\s*$)/g, '');
};
// 合并多個(gè)空白為一個(gè)空白
String.prototype.ResetBlank = function() {
var regEx = /\s+/g;
return this.replace(regEx, ' ');
};
// 保留數(shù)字
String.prototype.GetNum = function() {
var regEx = /[^\d]/g;
return this.replace(regEx, '');
};
// 保留中文
String.prototype.GetCN = function() {
var regEx = /[^\u4e00-\u9fa5\uf900-\ufa2d]/g;
return this.replace(regEx, '');
};
// String轉(zhuǎn)化為Number
String.prototype.ToInt = function() {
return isNaN(parseInt(this)) ? this.toString() : parseInt(this);
};
// 得到字節(jié)長(zhǎng)度
String.prototype.GetLen = function() {
var regEx = /^[\u4e00-\u9fa5\uf900-\ufa2d]+$/;
if (regEx.test(this)) {
return this.length * 2;
} else {
var oMatches = this.match(/[\x00-\xff]/g);
var oLength = this.length * 2 - oMatches.length;
return oLength;
}
};
// 獲取文件全名
String.prototype.GetFileName = function() {
var regEx = /^.*\/([^\/\?]*).*$/;
return this.replace(regEx, '$1');
};
// 獲取文件擴(kuò)展名
String.prototype.GetExtensionName = function() {
var regEx = /^.*\/[^\/]*(\.[^\.\?]*).*$/;
return this.replace(regEx, '$1');
};
//替換所有
String.prototype.replaceAll = function(reallyDo, replaceWith, ignoreCase)
{
if (!RegExp.prototype.isPrototypeOf(reallyDo)) {
return this.replace(new RegExp(reallyDo, (ignoreCase ? "gi" : "g")), replaceWith);
} else {
return this.replace(reallyDo, replaceWith);
}
};
//格式化字符串 add By 劉景寧 2010-12-09
String.Format = function() {
if (arguments.length == 0) {
return '';
}
if (arguments.length == 1) {
return arguments[0];
}
var reg = /{(\d+)?}/g;
var args = arguments;
var result = arguments[0].replace(reg, function($0, $1) {
return args[parseInt($1) + 1];
});
return result;
};
// 數(shù)字補(bǔ)零
Number.prototype.LenWithZero = function(oCount) {
var strText = this.toString();
while (strText.length < oCount) {
strText = '0' + strText;
}
return strText;
};
// Unicode還原
Number.prototype.ChrW = function() {
return String.fromCharCode(this);
};
// 數(shù)字?jǐn)?shù)組由小到大排序
Array.prototype.Min2Max = function() {
var oValue;
for (var i = 0; i < this.length; i++) {
for (var j = 0; j <= i; j++) {
if (this[i] < this[j]) {
oValue = this[i];
this[i] = this[j];
this[j] = oValue;
}
}
}
return this;
};
// 數(shù)字?jǐn)?shù)組由大到小排序
Array.prototype.Max2Min = function() {
var oValue;
for (var i = 0; i < this.length; i++) {
for (var j = 0; j <= i; j++) {
if (this[i] > this[j]) {
oValue = this[i];
this[i] = this[j];
this[j] = oValue;
}
}
}
return this;
};
// 獲得數(shù)字?jǐn)?shù)組中最大項(xiàng)
Array.prototype.GetMax = function() {
var oValue = 0;
for (var i = 0; i < this.length; i++) {
if (this[i] > oValue) {
oValue = this[i];
}
}
return oValue;
};
// 獲得數(shù)字?jǐn)?shù)組中最小項(xiàng)
Array.prototype.GetMin = function() {
var oValue = 0;
for (var i = 0; i < this.length; i++) {
if (this[i] < oValue) {
oValue = this[i];
}
}
return oValue;
};
// 獲取當(dāng)前時(shí)間的中文形式
Date.prototype.GetCNDate = function() {
var oDateText = '';
oDateText += this.getFullYear().LenWithZero(4) + new Number(24180).ChrW();
oDateText += this.getMonth().LenWithZero(2) + new Number(26376).ChrW();
oDateText += this.getDate().LenWithZero(2) + new Number(26085).ChrW();
oDateText += this.getHours().LenWithZero(2) + new Number(26102).ChrW();
oDateText += this.getMinutes().LenWithZero(2) + new Number(20998).ChrW();
oDateText += this.getSeconds().LenWithZero(2) + new Number(31186).ChrW();
oDateText += new Number(32).ChrW() + new Number(32).ChrW() + new Number(26143).ChrW() + new Number(26399).ChrW() + new String('26085199682010819977222352011620845').substr(this.getDay() * 5, 5).ToInt().ChrW();
return oDateText;
};
//擴(kuò)展Date格式化
Date.prototype.Format = function(format) {
var o = {
"M+": this.getMonth() + 1, //月份
"d+": this.getDate(), //日
"h+": this.getHours() % 12 == 0 ? 12 : this.getHours() % 12, //小時(shí)
"H+": this.getHours(), //小時(shí)
"m+": this.getMinutes(), //分
"s+": this.getSeconds(), //秒
"q+": Math.floor((this.getMonth() + 3) / 3), //季度
"S": this.getMilliseconds() //毫秒
};
var week = {
"0": "\u65e5",
"1": "\u4e00",
"2": "\u4e8c",
"3": "\u4e09",
"4": "\u56db",
"5": "\u4e94",
"6": "\u516d"
};
if (/(y+)/.test(format)) {
format = format.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
}
if (/(E+)/.test(format)) {
format = format.replace(RegExp.$1, ((RegExp.$1.length > 1) ? (RegExp.$1.length > 2 ? "\u661f\u671f" : "\u5468") : "") + week[this.getDay() + ""]);
}
for (var k in o) {
if (new RegExp("(" + k + ")").test(format)) {
format = format.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
}
}
return format;
}
Date.prototype.Diff = function(interval, objDate) {
//若參數(shù)不足或 objDate 不是日期類型則回傳 undefined
if (arguments.length < 2 || objDate.constructor != Date) { return undefined; }
switch (interval) {
//計(jì)算秒差
case 's': return parseInt((objDate - this) / 1000);
//計(jì)算分差
case 'n': return parseInt((objDate - this) / 60000);
//計(jì)算時(shí)差
case 'h': return parseInt((objDate - this) / 3600000);
//計(jì)算日差
case 'd': return parseInt((objDate - this) / 86400000);
//計(jì)算周差
case 'w': return parseInt((objDate - this) / (86400000 * 7));
//計(jì)算月差
case 'm': return (objDate.getMonth() + 1) + ((objDate.getFullYear() - this.getFullYear()) * 12) - (this.getMonth() + 1);
//計(jì)算年差
case 'y': return objDate.getFullYear() - this.getFullYear();
//輸入有誤
default: return undefined;
}
};
//檢測(cè)是否為空
Object.prototype.IsNullOrEmpty = function() {
var obj = this;
var flag = false;
if (obj == null || obj == undefined || typeof (obj) == 'undefined' || obj == '') {
flag = true;
} else if (typeof (obj) == 'string') {
obj = obj.trim();
if (obj == '') {//為空
flag = true;
} else {//不為空
obj = obj.toUpperCase();
if (obj == 'NULL' || obj == 'UNDEFINED' || obj == '{}') {
flag = true;
}
}
}
else {
flag = false;
}
return flag;