Question

What is the fastest way to implement the perl operator tr///?

For instance, if I were to have a String "ATGCATGC" and I use perl tr/GTCA/CAGT/ then I would get "TACGTACG".

Is there a single java function that does this?

Answer 1

As others have commented, Apache Commons StringUtils will do it for you. So will this method, though:

    public static String replaceChars(final String str, final String sourceChars, final String replaceChars) {

    int ix;
    final StringBuilder sb = new StringBuilder(str);
    for (int i = 0 ; i < sb.length() ; i++) {
        if ((ix = sourceChars.indexOf(sb.charAt(i))) != -1) {
            sb.replace(i, i + 1, replaceChars.substring(ix, ix + 1));
        }
    }

    return sb.toString();
}