Java String indexOf() | Java String lastIndexOf()

indexOf(String str)

Returns the index of the first occurrence of the specified substring within this string.

Syntax:

public int indexOf(String str)

 

Note: If no such occurrence of a substring within this string then it returns -1.

lastIndexOf(String str)

Returns the index of the last occurrence of the specified substring within this string.

Syntax:

public int lastIndexOf(String str)

 

Note: If no such occurrence of a substring within this string then it returns -1.

 

Example:

class TestString{
    String str = "www.w3schools.blog";

    public void indexOfTest(){
        System.out.println(str.indexOf("o"));
    }

    public void lastIndexOfTest(){
        System.out.println(str.lastIndexOf("o"));
    }
}

public class StringIndexTestExample {
    public static void main(String args[]){
        //creating TestString object
        TestString obj = new TestString();
        
        //method call
        obj.indexOfTest();
        obj.lastIndexOfTest();
    }
}

Output

9
18