How to replace a value conditionally in a Collection, such as replaceIf(Predicate)?

Question

Is there any easy way we could replace a value in a List or Collection if the value is null?

We can always do list.stream().filter(Objects::nonNu

Answer 1

Try this.

public static  void replaceIf(List list, Predicate predicate, T replacement) {
    for (int i = 0; i < list.size(); ++i)
        if (predicate.test(list.get(i)))
            list.set(i, replacement);
}

and

List list = Arrays.asList("a", "b", "c");
replaceIf(list, x -> x.equals("b"), "B");
System.out.println(list);
// -> [a, B, c]