.indexOf()

The .indexOf() method returns the zero-indexed position of the first occurrence of the given character(s) in a string. It returns -1 if the given characters(s) are not found.

string.indexOf(str, index)

• str can be a String, or an int representing a character or Unicode value. The index where this value is found will be returned.
• index is an optional index position in the string to start the search from.

The following example finds the position of the string “World” in “Hello World!”:

class FindIndex {
  public static void main(String[] args) {
    String greeting = "Hello World!";

    System.out.println(greeting.indexOf("World"));
  }
}

This outputs the following:

6