binaryStringDupes.java

public Boolean checkDupesBinary(String str) {
    char[] charArray = str.toCharArray();

    Boolean[] charSpot = new Boolean[256];

    for (char theChar : charArray ) {
        int charInt = (int) theChar;
        if (charSpot[charInt]) {
            return true;
        }
    }

    return false;
}