Transliteration in Java. Redefine each char in a string

Question

The aim of a method is a transliteration of strings, like: афиваў => afivaw. The problem is: I cannot use charAt method to redefine because there are some letters that demand to be transliterated as two symbols 'ш' => "sh". I try this:

public static String belrusToEngTranlit (String text){
    char[] abcCyr = {'a','б','в','г','д','ё','ж','з','и','к','л','м','н','п','р','с','т','у','ў','ф','х','ц','ш','щ','ы','э','ю','я'};
    String[] abcLat = {"a","b","v","g","d","jo","zh","z","i","k","l","m","n","p","r","s","t","u","w","f","h","ts","sh","sch","","e","ju","ja"};
    for (int i = 0; i < text.length(); i++) {
        for(int x = 0; x < abcCyr.length; x++ )
        if (text.charAt(i) == abcCyr[x]) {
            text.charAt(i) = abcLat[x];
        }
    }
    return text;
}

May be you can recommend me something except charAt?

Answer 1

String is immutable, so you can't change any text in it. So you can use StringBuilder to store result. See below code.

public static String belrusToEngTranlit (String text){
    char[] abcCyr = {'a','б','в','г','д','ё','ж','з','и','к','л','м','н','п','р','с','т','у','ў','ф','х','ц','ш','щ','ы','э','ю','я'};
    String[] abcLat = {"a","b","v","g","d","jo","zh","z","i","k","l","m","n","p","r","s","t","u","w","f","h","ts","sh","sch","","e","ju","ja"};

    StringBuilder builder = new StringBuilder();

    for (int i = 0; i < text.length(); i++) {
        for(int x = 0; x < abcCyr.length; x++ )
        if (text.charAt(i) == abcCyr[x]) {
            builder.append(abcLat[x]);
        }
    }
    return builder.toString();
}

Answer 2

String is immutable, you cannot set chars like this:
text.charAt(i) = abcLat[x]
This line is also syntactically incorrect
(let alone the immutability).

Look at StringBuilder.
This is what I can recommend.

The Cyrillic to Latin is easier, the opposite
(if you need it), will be a bit harder. Why?
Because e.g. you cannot just check for 's', you
need to inspect the next char too to see
if it is 'h' or not.

Answer 3

Strings are immutable (you can't change their contents), but with a small change to use a StringBuilder, which is a kind of mutable String, your code will work:

public static String belrusToEngTranlit (String text){
    char[] abcCyr = {'a','б','в','г','д','ё','ж','з','и','к','л','м','н','п','р','с','т','у','ў','ф','х','ц','ш','щ','ы','э','ю','я'};
    String[] abcLat = {"a","b","v","g","d","jo","zh","z","i","k","l","m","n","p","r","s","t","u","w","f","h","ts","sh","sch","","e","ju","ja"};
    StringBuilder english = new StringBuilder();
    outer:
    for (int i = 0; i < text.length(); i++) {
        for(int x = 0; x < abcCyr.length; x++ )
            if (text.charAt(i) == abcCyr[x]) {
                english.append(abcLat[x]);
                continue outer; // jump to next letter
            }
        // if no replacement made, use character as-is
        english.append(text.charAt(i));
    }
    return english.toString();
}

---

Note that there's the replaceEach() utility method in Apache's commons-lang library that does exactly this. Rather than reinvent the wheel, you could simply do this:

public static String belrusToEngTranlit (String text){
    String[] abcCyr = {"a","б","в","г","д","ё","ж","з","и","к","л","м","н","п","р","с","т","у","ў","ф","х","ц","ш","щ","ы","э","ю","я"};
    String[] abcLat = {"a","b","v","g","d","jo","zh","z","i","k","l","m","n","p","r","s","t","u","w","f","h","ts","sh","sch","","e","ju","ja"};
    return StringUtils.replaceEach(text, abcCyr, abcLat);
}