Java String lastIndexOf() method

The lastIndexOf() method in Java is a method of the String class. It is used to find the last occurrence (the rightmost occurrence) of a specified character or substring in a given string.

Find the last occurrence of a specified character

Syntax:

public int lastIndexOf(int ch)

int ch – A character (specified by its Unicode value) to search for.

Example:

public class LastIndexOfExample {
    public static void main(String[] args) {
        String str = "Hello World!";
        
        // Find the last occurrence of the character 'o'
        int index = str.lastIndexOf('o');
        System.out.println("Last index of 'o': " + index);
    }
}

Output: Last index of ‘o’: 7

Notes:

1. The method returns the index of the last occurrence of the specified character or substring.
2. If the character or substring is not found, it returns -1.

Find the last occurrence of a specified string

Syntax:

public int lastIndexOf(String str)

Example:

public class LastIndexOfExample {
    public static void main(String[] args) {
        String str = "Hello World Hello";
        
        // Find the last occurrence of the substring "Hello"
        int index = str.lastIndexOf("Hello");
        System.out.println("Last index of 'Hello': " + index);
    }
}

Output: Last index of ‘Hello’: 12

Find the string not found

public class LastIndexOfExample {
    public static void main(String[] args) {
        String str = "Hello World";
        
        // Find the last occurrence of the substring "Java"
        int index = str.lastIndexOf("Java");
        System.out.println("Last index of 'Java': " + index);
    }
}

Output: Last index of ‘Java’: -1

Find lastIndexOf() with a starting index

You can also specify a starting index from which the search will begin (searching backward).

public class LastIndexOfExample {
    public static void main(String[] args) {
        String str = "Hello World Hello";
        
        // Start search from index 5
        int index = str.lastIndexOf("Hello", 5);
        System.out.println("Last index of 'Hello' before index 5: " + index);
    }
}