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\"

<

Answer 1

Go through this method. visit for tricky code

public static boolean isSubString(String s, String sub) {
    int count = 0;
    for (int i = 0; i < s.length(); i++) {
        if (s.charAt(i) == sub.charAt(count)) {
            count++;
        } else {
            i-=count;
            count = 0;
        }
        if (count == sub.length()) {
            return true;
        }

    }
    return false;
}