javascript 函数原型

string .length 汉字为两个字符处理
.Tlength



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<script>
/*
This following code are designed and writen by Windy_sk <seasonx@163.net>
You can use it freely, but u must held all the copyright items!
*/

//测字符串实际长度
String.prototype.Tlength = function(){var arr=this.match(/[^\x00-\xff]/ig);return this.length+(arr==null?0:arr.length);}

//字符串左取
String.prototype.left = function(num,mode){if(!/\d+/.test(num))return(this);var str = this.substr(0,num);if(!mode) return str;var n = str.Tlength() - str.length;num = num - parseInt(n/2);return this.substr(0,num);}

//字符串右取
String.prototype.right = function(num,mode){if(!/\d+/.test(num))return(this);var str = this.substr(this.length-num);if(!mode) return str;var n = str.Tlength() - str.length;num = num - parseInt(n/2);return this.substr(this.length-num);}

//字符串包含
String.prototype.GetCount = function(str,mode){return eval("this.match(/("+str+")/g"+(mode?"i":"")+").length");}

//字符串去除两端空字符
String.prototype.Trim=function(){return this.replace(/(^\s*)|(\s*$)/g,"");}
String.prototype.Ltrim = function(){return this.replace(/(^\s*)/g, "");}
String.prototype.Rtrim = function(){return this.replace(/(\s*$)/g, "");}

document.write("''aa啦啦aa''.Tlength() = " + "aa啦啦aa".Tlength());
document.write("<br>");
document.write("''aabbclearcase/" target="_blank" >cc''.Tlength() = " + "aabbcc".Tlength());
document.write("<br>");
document.write("''aa啦啦aa''.left(4) = " + "aa啦啦aa".left(4));
document.write("<br>");
document.write("''aa啦啦aa''.left(4,true) = " + "aa啦啦aa".left(4,true));
document.write("<br>");
document.write("''aa啦啦aa''.right(4) = " + "aa啦啦aa".right(4));
document.write("<br>");
document.write("''aa啦啦aa''.right(4,true) = " + "aa啦啦aa".right(4,true));
document.write("<br>");
document.write("''abAcae''.GetCount(''a'') = " + "abAcae".GetCount("a"));
document.write("<br>");
document.write("''abAcae''.GetCount(''a'',true) = " + "abAcae".GetCount("a",true));
document.write("<br>");
document.write("'' abc de ''.Ltrim() = " + " abc de ".Ltrim());
document.write("<br>");
document.write("'' abc de ''.Rtrim() = " + " abc de ".Rtrim());
document.write("<br>");
document.write("'' abc de ''.Trim() = " + " abc de ".Trim());
</script>


再来几个函数，getCookie(),getQuery(),DateDiff(),DateAdd(),b2s()，原+改



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function getCookie(mainKey,subKey) {
var reg = new RegExp("(^| )"+mainKey+"=([^;]*)(;|$)");
var arr = document.cookie.match(reg);
if (arguments.length == 2) {
if (arr!=null)
return key(subKey,arr[2]);
else
return null;
} else if (arguments.length == 1) {
if (arr!=null)
return unescape(arr[2]);
else
return null;
}

function key(subKey,findWith) {
var arr,reg = new RegExp("(^| |&)"+subKey+"=([^&]*)(&|$)");
var findWith = findWith?findWith:document.cookie;
if (arr = findWith.match(reg))
return unescape(arr[2]);
else
return null;
}
}

function getQuery(name) {
var reg = new RegExp("(^|&)"+name+"=([^&]*)(&|$)");
var r = location.search.substr(1).match(reg)
if (r!=null) return unescape(r[2]);
}

function DateAdd(strInterval, NumDay, dtDate) {
var dtTmp = new Date(dtDate);
if (isNaN(dtTmp)) dtTmp = new Date();
switch (strInterval) {
case "s":return new Date(Date.parse(dtTmp) + (1000 * NumDay));
case "n":return new Date(Date.parse(dtTmp) + (60000 * NumDay));
case "h":return new Date(Date.parse(dtTmp) + (3600000 * NumDay));
case "d":return new Date(Date.parse(dtTmp) + (86400000 * NumDay));
case "w":return new Date(Date.parse(dtTmp) + ((86400000 * 7) * NumDay));
case "m":return new Date(dtTmp.getFullYear(), (dtTmp.getMonth()) + NumDay, dtTmp.getDate(), dtTmp.getHours(), dtTmp.getMinutes(), dtTmp.getSeconds());
case "y":return new Date((dtTmp.getFullYear() + NumDay), dtTmp.getMonth(), dtTmp.getDate(), dtTmp.getHours(), dtTmp.getMinutes(), dtTmp.getSeconds());
}
}
// DateDiff("m","2002/12/1 00:00:00","2004/12/1 00:00:00")
function DateDiff(strInterval, dtStart, dtEnd) {
var dtStart = new Date(dtStart);
if (isNaN(dtStart)) dtStart = new Date();
var dtEnd = new Date(dtEnd);
if (isNaN(dtEnd)) dtEnd = new Date();
switch (strInterval) {
case "s":return parseInt((dtEnd - dtStart) / 1000);
case "n":return parseInt((dtEnd - dtStart) / 60000);
case "h":return parseInt((dtEnd - dtStart) / 3600000);
case "d":return parseInt((dtEnd - dtStart) / 86400000);
case "w":return parseInt((dtEnd - dtStart) / (86400000 * 7));
case "m":return (dtEnd.getMonth()+1)+((dtEnd.getFullYear()-dtStart.getFullYear())*12) - (dtStart.getMonth()+1);
case "y":return dtEnd.getFullYear() - dtStart.getFullYear();
}
}
// b2s("11新浪网!@#程序员_+}{:><")
function b2s(strng) {
var Matches = strng.match(/[\x21-\x7e]/g);
for (var i=0;i<Matches.length;i++) {
strng = strng.replace(Matches[i],String.fromCharCode(Matches[i].charCodeAt (0)+65248))
}
return strng;
}

来几个，IE5下原型扩展



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/*Number Object*/
if(!Number.prototype.toFixed) {
Number.prototype.toFixed = function(n) {
with(Math) return round(Number(this)*pow(10,n))/pow(10,n)
}
}
/*Array Object*/
if (!Array.prototype.pop) {
Array.prototype.pop = function() {
var lastElement = this[this.length-1];
this.length = Math.max(this.length-1,0);
return lastElement;
}
}
if (!Array.prototype.push) {
Array.prototype.push = function() {
for(var i=0;i<arguments.length;i++) {
this[this.length]=arguments[i];
}
return this.length;
}
}
if (!Array.prototype.shift) {
Array.prototype.shift = function() {
var firstElement = this[0];
this.reverse();
this.pop();
this.reverse();
return firstElement;
}
}
if (!Array.prototype.splice) {
Array.prototype.splice = function() {
var start = arguments[0];
var deleteCount = start+arguments[1];
var deleteItem = this.slice(start,deleteCount);
var beforeItem = this.slice(0,start);
var afterItem = this.slice(deleteCount);
this.length=beforeItem.length;
var i;
for (i=2;i<arguments.length;this[this.length]=arguments[i++]);
for (i=0;i<afterItem.length;this[this.length]=afterItem[i++]);
return deleteItem;
}
}
if (!Array.prototype.unshift) {
Array.prototype.unshift = function() {
var arr = new Array();
for (var i=0;i<arguments.length;arr[i]=arguments[i++]);
arr = arr.concat(this);
this.length = 0;
for (i=0;i<arr.length;this[i]=arr[i++]);
}
}

原文转自：http://www.ltesting.net