分享10个原生JavaScript技巧
编程学习 2021-07-04 21:47www.dzhlxh.cn编程入门
本文给大家分享的是个人总结的10条非常常用的原生javascript的小技巧，都是平时项目中用到的，这里总结记录下来，有需要的小伙伴可以参考下。
1、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 < 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、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、清除空格
String.prototype.trim = function() {
var reExtraSpace = /^\s*(.*?)\s+$/;
return this.replace(reExtraSpace, "$1")
}
4、替换全部
String.prototype.replaceAll = function(s1, s2) {
return this.replace(new RegExp(s1, "gm"), s2)
}
5、转义html标签
function HtmlEncode(text) {
return text.replace(/&/g, '&').replace(/\"/g, '"').replace(/</g, '<').replace(/>/g, '>')
}
6、还原html标签
代码如下:
function HtmlDecode(text) {
return text.replace(/&/g, '&').replace(/"/g, '\"').replace(/</g, '<').replace(/>/g, '>')
}
7、时间日期格式转换
Date.prototype.Format = function(formatStr) {
var str = formatStr;
var Week = ['日', '一', '二', '三', '四', '五', '六'];
str = str.replace(/yyyy|YYYY/, this.getFullYear());
str = str.replace(/yy|YY/, (this.getYear() % 100) > 9 ? (this.getYear() % 100).toString() : '0' + (this.getYear() % 100));
str = str.replace(/MM/, (this.getMonth() + 1) > 9 ? (this.getMonth() + 1).toString() : '0' + (this.getMonth() + 1));
str = str.replace(/M/g, (this.getMonth() + 1));
str = str.replace(/w|W/g, Week[this.getDay()]);
str = str.replace(/dd|DD/, this.getDate() > 9 ? this.getDate().toString() : '0' + this.getDate());
str = str.replace(/d|D/g, this.getDate());
str = str.replace(/hh|HH/, this.getHours() > 9 ? this.getHours().toString() : '0' + this.getHours());
str = str.replace(/h|H/g, this.getHours());
str = str.replace(/mm/, this.getMinutes() > 9 ? this.getMinutes().toString() : '0' + this.getMinutes());
str = str.replace(/m/g, this.getMinutes());
str = str.replace(/ss|SS/, this.getSeconds() > 9 ? this.getSeconds().toString() : '0' + this.getSeconds());
str = str.replace(/s|S/g, this.getSeconds());
return str
}
8、判断是否为数字类型
function isDigit(value) {
var patrn = /^[0-9]*$/;
if (patrn.exec(value) == null || value == "") {
return false
} else {
return true
}
}
9、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、获取cookie值
function getCookie(name) {
var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));
if (arr != null) return unescape(arr[2]);
return null
以上所述就是本文的全部内容了，希望大家能够喜欢。