原生JavaScript技巧大收集(1~10)

1、原生JavaScript实现字符串长度截取

01 function cutstr(str, len) {
02     var temp;
03     var icount = 0;
04     var patrn = /[^x00-xff]/;
05     var strre = "";
06     for (var i = 0; i < str.length; i++) {
07         if (icount < len - 1) {
08             temp = str.substr(i, 1);
09             if (patrn.exec(temp) == null) {
10                 icount = icount + 1
11             } else {
12                 icount = icount + 2
13             }
14             strre += temp
15         } else {
16             break
17         }
18     }
19     return strre + "..."
20 }


2、原生JavaScript获取域名主机

01 function getHost(url) {
02     var host = "null";
03     if(typeof url == "undefined"|| null == url) {
04         url = window.location.href;
05     }
06     var regex = /^w+://([^/]*).*/;
07     var match = url.match(regex);
08     if(typeof match != "undefined" && null != match) {
09         host = match[1];
10     }
11     return host;
12 }


3、原生JavaScript清除空格

1 String.prototype.trim = function() {
2     var reExtraSpace = /^s*(.*?)s+$/;
3     return this.replace(reExtraSpace, "$1")
4 }


4、原生JavaScript替换全部

1 String.prototype.replaceAll = function(s1, s2) {
2     return this.replace(new RegExp(s1, "gm"), s2)
3 }


5、原生JavaScript转义html标签

1 function HtmlEncode(text) {
2     return text.replace(/&/g, '&amp').replace(/"/g, '&quot;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
3 }


6、原生JavaScript还原html标签

1 function HtmlDecode(text) {
2     return text.replace(/&amp;/g, '&').replace(/&quot;/g, '"').replace(/&lt;/g, '<').replace(/&gt;/g, '>')
3 }


7、原生JavaScript时间日期格式转换

01 Date.prototype.Format = function(formatStr) {
02     var str = formatStr;
03     var Week = ['日', '一', '二', '三', '四', '五', '六'];
04     str = str.replace(/yyyy|YYYY/, this.getFullYear());
05     str = str.replace(/yy|YY/, (this.getYear() % 100) > 9 ? (this.getYear() % 100).toString() : '0' + (this.getYear() % 100));
06     str = str.replace(/MM/, (this.getMonth() + 1) > 9 ? (this.getMonth() + 1).toString() : '0' + (this.getMonth() + 1));
07     str = str.replace(/M/g, (this.getMonth() + 1));
08     str = str.replace(/w|W/g, Week[this.getDay()]);
09     str = str.replace(/dd|DD/, this.getDate() > 9 ? this.getDate().toString() : '0' + this.getDate());
10     str = str.replace(/d|D/g, this.getDate());
11     str = str.replace(/hh|HH/, this.getHours() > 9 ? this.getHours().toString() : '0' + this.getHours());
12     str = str.replace(/h|H/g, this.getHours());
13     str = str.replace(/mm/, this.getMinutes() > 9 ? this.getMinutes().toString() : '0' + this.getMinutes());
14     str = str.replace(/m/g, this.getMinutes());
15     str = str.replace(/ss|SS/, this.getSeconds() > 9 ? this.getSeconds().toString() : '0' + this.getSeconds());
16     str = str.replace(/s|S/g, this.getSeconds());
17     return str
18 }


8、原生JavaScript判断是否为数字类型

1 function isDigit(value) {
2     var patrn = /^[0-9]*$/;
3     if (patrn.exec(value) == null || value == "") {
4         return false
5     } else {
6         return true
7     }
8 }


9、原生JavaScript设置cookie值

1 function setCookie(name, value, Hours) {
2     var d = new Date();
3     var offset = 8;
4     var utc = d.getTime() + (d.getTimezoneOffset() * 60000);
5     var nd = utc + (3600000 * offset);
6     var exp = new Date(nd);
7     exp.setTime(exp.getTime() + Hours * 60 * 60 * 1000);
8     document.cookie = name + "=" + escape(value) + ";path=/;expires=" + exp.toGMTString() + ";domain=360doc.com;"
9 }


10、原生JavaScript获取cookie值

1 function getCookie(name) {
2     var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));
3     if (arr != null) return unescape(arr[2]);
4     return null
5 }
原文地址:https://www.cnblogs.com/LoveOrHate/p/4310164.html