03.05.2010 12:30:09

UTF-8 (De)Kodierer

weniger reden - mehr Code:

Kodieren

Code:ausführenändern

function encodeUTF8(str){

    var ret = "";
    for (var i = 0; i < str.length; i++){
        var chr = str.charCodeAt(i);
        if (chr < 128){
            ret += str.charAt(i);
        }
        else{
            var blocks = new Array();
            var beginn = 128;
            var plus = 128;
            while (beginn + chr > 255 - (plus >> 1)){
                var last = (63 & chr) + 128;
                chr = chr >> 6;
                plus = plus >> 1;
                beginn += plus;
                blocks.push(last);
            }
            blocks.push(beginn + chr);
            
            for (var j = blocks.length - 1; j >= 0; j--){
                ret += String.fromCharCode(blocks[j]);
            }
        }
    }
    return ret;
};

Dekodieren

Code:ausführenändern

function decodeUTF8(str){

    var errorChar = String.fromCharCode(65533);
    var btes = new Array(str.length);
    for (var i = 0; i < str.length; i++){
        btes[i] = str.charCodeAt(i);
    }
    var ret = "";
    for (var i = 0; i < btes.length; i++){
        if (btes[i] < 128){
            ret += str.charAt(i);
            continue;
        }
        if (btes[i] < 192){
            ret += errorChar;
            continue;
        }
        var block = btes[i];
        var error = false;
        var length = 0;
        while ((((128>>length)|block) == block) && (block > 0)){
            block -= 128>>length;
            length++;
        }
        for (var j = 1; j < length; j++){
            var help = btes[i + j];
            if (help < 128 || help >= 192){
                error = true;
                break;
            }
            help -= 128;
            block = (block<<6) + help;
        }
        i += length - 1;
        
        if (error){
            ret += errorChar;
        }
        else {
            ret += String.fromCharCode(block);
        }
    }
    
    return ret;
};