此类技巧还有很多，欢迎继续分享

解析 URL

从 James Padolsey 的 Blog 中看到的个小技巧，就是利用 a 标签的 DOM 属性解析 URL 字符串。

// This function creates a new anchor element and uses location
// properties (inherent) to get the desired URL data. Some String
// operations are used (to normalize results across browsers).
 
function parseURL(url) {
    var a =  document.createElement('a');
    a.href = url;
    return {
        source: url,
        protocol: a.protocol.replace(':',''),
        host: a.hostname,
        port: a.port,
        query: a.search,
        params: (function(){
            var ret = {},
                seg = a.search.replace(/^\?/,'').split('&'),
                len = seg.length, i = 0, s;
            for (;i<len;i++) {
                if (!seg[i]) { continue; }
                s = seg[i].split('=');
                ret[s[0]] = s[1];
            }
            return ret;
        })(),
        file: (a.pathname.match(/\/([^\/?#]+)$/i) || [,''])[1],
        hash: a.hash.replace('#',''),
        path: a.pathname.replace(/^([^\/])/,'/$1'),
        relative: (a.href.match(/tp:\/\/[^\/]+(.+)/) || [,''])[1],
        segments: a.pathname.replace(/^\//,'').split('/')
    };
}

可对比下「传统的」正则解析方式（ 取自 Tbra 库 ），至少上面代码看起来更容易理解得多

parseURL: (function() {
    var keys = ['source', 
                'prePath', 
                'scheme', 
                'username', 
                'password', 
                'host', 
                'port', 
                'path', 
                'dir', 
                'file',
                'query', 
                'fragment'];
    var re = /^((?:([^:\/?#.]+):)?(?:\/\/)?(?:([^:@]*):?([^:@]*)?@)?([^:\/?#]*)(?::(\d*))?) \
               ((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*)) \
               (?:\?([^#]*))?(?:#(.*))?/;    
    return function(sourceUri) {
        var uri = {};
        var uriParts = re.exec(sourceUri);
        for(var i = 0; i < uriParts.length; ++i) {
            uri[keys[i]] = (uriParts[i] ? uriParts[i] : '');
        }
        return uri;
    }
})();

（反）转义 HTML

取自 Prototype 中的相应代码

escapeHTML: function(str) {
    var div  = document.createElement('div');
    var text = document.createTextNode(str);
    div.appendChild(text);
    return div.innerHTML;
}

unescapeHTML: function(str) {
    var div       = document.createElement('div');
    div.innerHTML = str.replace(/<\/?[^>]+>/gi, '');
    return div.childNodes[0] ? div.childNodes[0].nodeValue : '';
}

-- EOF --