javascript的html编码函数 (htmlSpecialChars-处理特殊字符)

    function htmlSpecialChars(str)    
    {    
        str = str.replace(/&/g, '&');  
        str = str.replace(/</g, '&lt;');  
        str = str.replace(/>/g, '&gt;');  
        str = str.replace(/"/g, '&quot;');  
        str = str.replace(/'/g, '&#039;');  
        return str;  
    }  
      
    //这个版本多转换了一些内容  
        function htmlSpecialChars(str)    
        {    
            var s = "";  
            if (str.length == 0) return "";  
            for   (var i=0; i<str.length; i++)  
            {  
                switch (str.substr(i,1))  
                {  
                    case "<": s += "&lt;"; break;  
                    case ">": s += "&gt;"; break;  
                    case "&": s += "&amp;"; break;  
                    case " ":  
                        if(str.substr(i + 1, 1) == " "){  
                            s += " &nbsp;";  
                            i++;  
                        } else s += " ";  
                        break;  
                    case "\"": s += "&quot;"; break;  
                    case "\n": s += "<br>"; break;  
                    default: s += str.substr(i,1); break;  
                }  
            }  
            return s;  
        }