How to know if the string variabel contains only space in java?

Question

I have a variable that\'s a string and I want to replace the string with \"null\" if the variable contains only a space or multiple spaces. How can I do it?

Answer 1

This is a way you could do it:

    String spaces = "   -- - -";
    if (spaces.matches("[ -]*")) {
        System.out.println("Only spaces and/or - or empty");
    }
    else {
        System.out.println("Not only spaces");
    }