Another powerful reason for using tuples is to return multiple values from a single method. Declare the method return type using one of the named tuple types. Then use the from() method to return the values.

private Pair<Boolean, Integer> findCharacter(String string, char c) {
    int index = string.indexOf(c);
    if (index == -1)
        return Tuple.from(false, 0);
    else
        return Tuple.from(true, index);
}

It is best to use the Variable class and extract() method to retrieve values so that the tuple never needs to be stored when calling the method.

Variable<Boolean> found = new Variable<Boolean>();
Variable<Integer> index = new Variable<Integer>();

findCharacter("Hello, world", 'w').
    extract(found).extract(index);
if (found.get()) {
    int i = index.get();
    // i = 7
}

If you would rather return values via parameters, the Variable class can be used instead of the traditional single-valued array. Use the set() method to assign a value to a Variable.

private boolean findCharacter(String string, char c,
    Variable<Integer> indexRef) {
    int index = string.indexOf(c);
    if (index == -1)
        return false;
    else {
        indexRef.set(index);
        return true;
    }
}

Variable<Integer> index = new Variable<Integer>();

if (findCharacter("Hello, world", 'w', index)) {
    int i = index.get();
    // i = 7
}