javascript学习笔记之10个原生技巧_javascript技巧

1、原生JavaScript实现字符串长度截取

function cutstr(str, len) {
var temp;
var icount = 0;
var patrn = /[^\x00-\xff]/;
var strre = "";
for (var i = 0; i if (icount temp = str.substr(i, 1);
if (patrn.exec(temp) == null) {
icount = icount + 1
} else {
icount = icount + 2
}
strre += temp
} else {
break
}
}
return strre + "..."
}

2、原生JavaScript获取域名主机

function getHost(url) {
var host = "null";
if(typeof url == "undefined"|| null == url) {
url = window.location.href;
}
var regex = /^\w+\:\/\/([^\/]*).*/;
var match = url.match(regex);
if(typeof match != "undefined" && null != match) {
host = match[1];
}
return host;
}

3、原生JavaScript清除空格

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

4、原生JavaScript替换全部

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

5、原生JavaScript转义html标签

function HtmlEncode(text) {
return text.replace(/&/g, '&amp').replace(/\"/g, '"').replace(/, '/g, '>')
}

6、原生JavaScript还原html标签

function HtmlDecode(text) {
return text.replace(/&/g, '&').replace(/"/g, '\"').replace(/, '/g, '>')
}

7、原生JavaScript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());
str = str.replace(/d|D/g, this.getDate());
str = str.replace(/hh|HH/, this.getHours() > 9 ? this.getHours().toString() : '0' + this.getHours());
str = str.replace(/h|H/g, this.getHours());
str = str.replace(/mm/, this.getMinutes() > 9 ? this.getMinutes().toString() : '0' + this.getMinutes());
str = str.replace(/m/g, this.getMinutes());
str = str.replace(/ss|SS/, this.getSeconds() > 9 ? this.getSeconds().toString() : '0' + this.getSeconds());
str = str.replace(/s|S/g, this.getSeconds());
return str
}

8、原生JavaScript判断是否为数字类型

function isDigit(value) {
var patrn = /^[0-9]*$/;
if (patrn.exec(value) == null || value == "") {
return false
} else {
return true
}
}

9、原生JavaScript设置cookie值

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

10、原生JavaScript获取cookie值

function getCookie(name) {
var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));
if (arr != null) return unescape(arr[2]);
return null
}