Java String - indexOf() Method

The java.lang.String.indexOf() method is used to find out the index number for first occurrence of specified substring in the specified substring of the given string starting at the specified index.

Syntax

public int indexOf(String str, int fromIndex)

Parameters

`str`	specify the substring to search for.
`fromIndex`	specify the index from which to start the search.

Return Value

Returns the index of the first occurrence of the specified substring, starting at the specified index, or -1 if there is no such occurrence.

Exception

NA.

Example:

Here, the indexOf() method is used to find out the index number for first occurrence of specified substring in the given string.

import java.lang.*;

public class MyClass {
  public static void main(String[] args) {
    String MyString = "Java is a programming language. Learning Java is fun.";

    //index number of first occurrence 
    //of "is" in the given substring
    System.out.println(MyString.indexOf("is", 20));   
  }
}

The output of the above code will be:

❮ Java.lang - String