How to know if a given string is substring from another string in Java

Question

Hi I have to compute if a given string is substring of a bigger string. For example

String str = "Hallo my world";
String substr = "my"

The method "contains" should return true because str contains substr (false otherwise).

I was looking for something like "contains" at the String class but I didn't find it. I suppose that the only solution is to use pattern matching. If this is the case which would be the better (cheapest) way to do this?

Thanks!

Answer 1

There is a contains() method! It was introduced in Java 1.5. If you are using an earlier version, then it's easy to replace it with this:

str.indexOf(substr) != -1

Answer 2

 String str="hello world";
        System.out.println(str.contains("world"));//true
        System.out.println(str.contains("world1"));//false

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