js 小技巧

js 实现 base64 加密解密

// 创建Base64对象  
var Base64={_keyStr:"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",encode:function(e){var t="";var n,r,i,s,o,u,a;var f=0;e=Base64._utf8_encode(e);while(f<e.length){n=e.charCodeAt(f++);r=e.charCodeAt(f++);i=e.charCodeAt(f++);s=n>>2;o=(n&3)<<4|r>>4;u=(r&15)<<2|i>>6;a=i&63;if(isNaN(r)){u=a=64}else if(isNaN(i)){a=64}t=t+this._keyStr.charAt(s)+this._keyStr.charAt(o)+this._keyStr.charAt(u)+this._keyStr.charAt(a)}return t},decode:function(e){var t="";var n,r,i;var s,o,u,a;var f=0;e=e.replace(/[^A-Za-z0-9+/=]/g,"");while(f<e.length){s=this._keyStr.indexOf(e.charAt(f++));o=this._keyStr.indexOf(e.charAt(f++));u=this._keyStr.indexOf(e.charAt(f++));a=this._keyStr.indexOf(e.charAt(f++));n=s<<2|o>>4;r=(o&15)<<4|u>>2;i=(u&3)<<6|a;t=t+String.fromCharCode(n);if(u!=64){t=t+String.fromCharCode(r)}if(a!=64){t=t+String.fromCharCode(i)}}t=Base64._utf8_decode(t);return t},_utf8_encode:function(e){e=e.replace(/rn/g,"n");var t="";for(var n=0;n<e.length;n++){var r=e.charCodeAt(n);if(r<128){t+=String.fromCharCode(r)}else if(r>127&&r<2048){t+=String.fromCharCode(r>>6|192);t+=String.fromCharCode(r&63|128)}else{t+=String.fromCharCode(r>>12|224);t+=String.fromCharCode(r>>6&63|128);t+=String.fromCharCode(r&63|128)}}return t},_utf8_decode:function(e){var t="";var n=0;var r=c1=c2=0;while(n<e.length){r=e.charCodeAt(n);if(r<128){t+=String.fromCharCode(r);n++}else if(r>191&&r<224){c2=e.charCodeAt(n+1);t+=String.fromCharCode((r&31)<<6|c2&63);n+=2}else{c2=e.charCodeAt(n+1);c3=e.charCodeAt(n+2);t+=String.fromCharCode((r&15)<<12|(c2&63)<<6|c3&63);n+=3}}return t}}  
  
// 定义字符串  
var string = 'Hello World!';  
  
// 加密  
var encodedString = Base64.encode(string);  
console.log(encodedString); // 输出: "SGVsbG8gV29ybGQh"  
  
// 解密  
var decodedString = Base64.decode(encodedString);  
console.log(decodedString); // 输出: "Hello World!"  

js 去除html 标签和空格 

/** 
 * 去掉html标签和所有空格 
 * @param str 
 * @returns {*} 
 */  

// 方法1
function removeHTMLTag(str) {  
    str = str.replace(/</?[^>]*>/g, ''); //去除HTML tag  
    str = str.replace(/[ | ]*
/g, '
'); //去除行尾空白  
    str = str.replace(/ /ig, '');//去掉   
    str = Trim(str, "g");  
    return str;  
}  

// 方法2
function Trim(str, is_global) {  
    var result;  
    result = str.replace(/(^s+)|(s+$)/g, "");  
    if (is_global.toLowerCase() == "g") {  
        result = result.replace(/s/g, "");  
    }  
    return result;  
}  
console.log(removeHTMLTag('<a>test</a>'));  

// 方法3 利用jq 的text()方法

console.log($('<a>test</a>').text());