Java lastIndexOf Method

The Java lastIndexOf Method is one of the Java String Method which is used to return the index position of the last occurrence of a specified string. If the specified string is not found, It will return -1. In this article we will show you, How to use String.lastIndexOf in Java Programming language with example. Before we get into the example, let us see the basic syntax of the string lastIndexOf in Java Programming language is as shown below.

Java lastIndexOf Method syntax

The Java Programming Language provides four different methods to return the index position of the last occurrence. Following method will accept the character as the parameter and return the index position of the last occurrence of the specified character.

public int lastIndexOf(int ch); // It will return Integer

//In order to use in program

String_Object.lastIndexOf(int ch)

Following method will accept the character as the first parameter and last index position (End_index) as the second argument. Java String.lastIndexOf method will start looking from index position 0 to the End_index index position and returns the last occurrence of the specified character.

public int lastIndexOf(int ch, int End_Index); // It will return Integer

//In order to use in program

String_Object.lastIndexOf(int ch, int End_Index)

Following method will accept the string data as the argument and return the index position of the last occurrence of the specified substring.

public int lastIndexOf(String str); // It will return Integer

//In order to use in program

String_Object.lastIndexOf(String str)

Following method will accept the string data as the first parameter and last index position (End_index) as the second argument. Java String.lastIndexOf method will start looking from index position 0 to the End_index index position and returns the last occurrence of the specified substring.

public int lastIndexOf(String str, int End_Index); // It will return Integer

//In order to use in program

String_Object.lastIndexOf(String str, int Starting_Index)

String_Object: Please specify the valid String Object.
End_Index: Please specify the ending index position. If you specify this value then, string.lastIndexOf function will start looking from index position 0 to this position (not to the end).

NOTE: If you specify the negative value as the End_Index then, Java String.lastIndexOf function will return -1.

Java lastIndexOf Method Example

The Java string lastIndexOf method is used to return the index position of the last occurrence of a specified string. This Java program will help you to understand the Java string.lastIndexOfmethod.

JAVA CODE

//Java String lastIndexOf example

package StringFunctions;

public class LastIndexOfMethod {

public static void main(String[] args) {

String str = "Tutorials On Java Programming";

String str1 = "We are abc working at abc company";

int a = str.lastIndexOf('i');

int b = str.lastIndexOf('i', 10);

int c = str.lastIndexOf('i', -10);

int d = str.lastIndexOf('y');

int e = str1.lastIndexOf("abc");

int f = str1.lastIndexOf("abc", 21);

int g = str1.lastIndexOf("abc", 29);

int h = str1.lastIndexOf("abc", -25);

System.out.println( "Last Index position of i = " + a);

System.out.println( "Starting from 10 - Last Index position of i = " + b);

System.out.println( "Start from -Ve Index - Last Index position of i = " + c);

System.out.println( "Last Index position of y = " + d);

System.out.println( "Last Index position of String abc = " + e);

System.out.println( "Starting from 10 - Last Index position of String abc = " + f);

System.out.println( "Starting from 25 - Last Index position of String abc = " + g);

System.out.println( "Start from -Ve Index - Last Index position of String abc = " + h);

}

OUTPUT

ANALYSIS

First we declared two String variables Str1, Str2 and assigned corresponding values using following statement

1 2	String str = "Tutorials On Java Programming"; String str1 = "We are abc working at abc company";

Following statement will call the public int lastIndexOf (int ch) method to find the index position of last occurred ‘i’

1	int a = str.lastIndexOf('i');

Following statement will call the public int lastIndexOf (int ch, int End_Index) method to find the index position of ‘i’ starting from index position 0 to index position 10. As we all know that, i is located only once before the index position 10 so, function has return the the same

1	int b = str.lastIndexOf('i', 10);

Next we used the negative value as the End_Index.

1	int c = str.lastIndexOf('i', -10);

In the next line we are looking for non existing item ‘y’ inside the str. This will call the public int lastIndexOf (int ch) method to find the last index position of ‘y’ since it doesn’t find, it is returning -1 as output

1	int d = str.lastIndexOf('y');

Following statement will call the public int lastIndexOf (String str) method to find the index position of a substring ‘abc’ and store the last index value in variable e.

1	int e = str1.lastIndexOf("abc");

NOTE: You should count the space as One Character.

From the above statement you can observe that, although term abc is repeated multiple times, Java string lastIndexof function is returning the index position of a last occurrence. Now, let us provide the end index position. Following statement will call the public int lastIndexOf(String str, int End_Index) method to return the last occurrence of string abc starting at index position 0 to 21.

1	int f = str1.lastIndexOf("abc", 21);

Let us change the End_Index value to 29. It means, it return the last occurrence of string abc starting at index position 0 to 29.

1	int g = str1.lastIndexOf("abc", 29);

Lastly we used System.out.println statements to print the output

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Java lastIndexOf Method syntax

Java lastIndexOf Method Example

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