JS中字符串trim()使用示例

2024-05-06 16:20:51

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本文主要给大家介绍的是javascript中的扩展方法字符串trim()的使用指南，十分的简单实用，有需要的小伙伴可以参考下。

示例一：

<head>

<title>测试JS扩展方法</title>

<script type="text/javascript">

// 合并多个空白为一个空白

String.prototype.ResetBlank = function() { //对字符串扩展

var regEx = //s+/g;

return this.replace(regEx, ' ');

};

window.onload = function()

{

var str = "你在他想还好吗?";

alert(str);

str = str.ResetBlank(); //这样就能够调用了，跟C#的很像吧!

alert(str);

}

</script>

</head>

示例二：

// 清除两边的空格

String.prototype.trim = function() {

return this.replace(/(^/s*)|(/s*$)/g, '');

};

// 合并多个空白为一个空白

String.prototype.ResetBlank = function() {

var regEx = //s+/g;

return this.replace(regEx, ' ');

};

// 保留数字

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转化为Number

String.prototype.ToInt = function() {

return isNaN(parseInt(this)) ? this.toString() : parseInt(this);

};

// 得到字节长度

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;

}

};

// 获取文件全名

String.prototype.GetFileName = function() {

var regEx = /^.*//([^///?]*).*$/;

return this.replace(regEx, '$1');

};

// 获取文件扩展名

String.prototype.GetExtensionName = function() {

var regEx = /^.*//[^//]*(/.[^/./?]*).*$/;

return this.replace(regEx, '$1');

};

//替换所有

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 刘景宁 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;

};

// 数字补零

Number.prototype.LenWithZero = function(oCount) {

var strText = this.toString();

while (strText.length < oCount) {

strText = '0' + strText;

}

return strText;

};

// Unicode还原

Number.prototype.ChrW = function() {

return String.fromCharCode(this);

};

// 数字数组由小到大排序

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;

};

// 数字数组由大到小排序

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;

};

// 获得数字数组中最大项

Array.prototype.GetMax = function() {

var oValue = 0;

for (var i = 0; i < this.length; i++) {

if (this[i] > oValue) {

oValue = this[i];

}

}

return oValue;

};

// 获得数字数组中最小项

Array.prototype.GetMin = function() {

var oValue = 0;

for (var i = 0; i < this.length; i++) {

if (this[i] < oValue) {

oValue = this[i];

}

}

return oValue;

};

// 获取当前时间的中文形式

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;

};

//扩展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, //小时

"H+": this.getHours(), //小时

"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) {

//若参数不足或 objDate 不是日期类型則回传 undefined

if (arguments.length < 2 || objDate.constructor != Date) { return undefined; }

switch (interval) {

//计算秒差

case 's': return parseInt((objDate - this) / 1000);

//计算分差

case 'n': return parseInt((objDate - this) / 60000);

//计算時差

case 'h': return parseInt((objDate - this) / 3600000);

//计算日差

case 'd': return parseInt((objDate - this) / 86400000);

//计算周差

case 'w': return parseInt((objDate - this) / (86400000 * 7));

//计算月差

case 'm': return (objDate.getMonth() + 1) + ((objDate.getFullYear() - this.getFullYear()) * 12) - (this.getMonth() + 1);

//计算年差

case 'y': return objDate.getFullYear() - this.getFullYear();

//输入有误

default: return undefined;

}

};

//检测是否为空

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 == '') {//为空

flag = true;

} else {//不为空

obj = obj.toUpperCase();

if (obj == 'NULL' || obj == 'UNDEFINED' || obj == '{}') {

flag = true;

}

}

}

else {

flag = false;

}

return flag;