JavaScript常用方法函数收集
本文中，收集了一些比较常用的Javascript函数，希望对学习JS的朋友们有所帮助。
1. 字符串长度截取
function cutstr(str, len) {
var temp,
icount = 0,
patrn = /[^\x00-\xff]/，
strre = "";
for (var i = 0; i < str.length; i++) {
if (icount < len - 1) {
temp = str.substr(i, 1);
if (patrn.exec(temp) == null) {
icount = icount + 1
} else {
icount = icount + 2
}
strre += temp
} else {
break;
}
}
return strre + "..."
}
2. 替换全部
String.prototype.replaceAll = function(s1, s2) {
return this.replace(new RegExp(s1, "gm"), s2)
}
3. 清除空格
String.prototype.trim = function() {
var reExtraSpace = /^\s*(.*?)\s+$/;
return this.replace(reExtraSpace, "$1")
}
4. 清除左空格/右空格
function ltrim(s){ return s.replace( /^(\s*| *)/, ""); }
function rtrim(s){ return s.replace( /(\s*| *)$/, ""); }
5. 判断是否以某个字符串开头
String.prototype.startWith = function (s) {
return this.indexOf(s) == 0
}
6. 判断是否以某个字符串结束
String.prototype.endWith = function (s) {
var d = this.length - s.length;
return (d >= 0 && this.lastIndexOf(s) == d)
}
7. 转义html标签
function HtmlEncode(text) {
return text.replace(/&/g, '&').replace(/\"/g, '"').replace(/</g, '<').replace(/>/g, '>')
}
8. 时间日期格式转换
Date.prototype.Format = function(formatStr) {
var str = formatStr;
var Week = ['日', '一', '二', '三', '四', '五', '六'];
str = str.replace(/yyyy|YYYY/, this.getFullYear());
str = str.replace(/yy|YY/, (this.getYear() % 100) > 9 ? (this.getYear() % 100).toString() : '0' + (this.getYear() % 100));
str = str.replace(/MM/, (this.getMonth() + 1) > 9 ? (this.getMonth() + 1).toString() : '0' + (this.getMonth() + 1));
str = str.replace(/M/g, (this.getMonth() + 1));
str = str.replace(/w|W/g, Week[this.getDay()]);
str = str.replace(/dd|DD/, this.getDate() > 9 ? this.getDate().toString() : '0' + this.getDate());