Java Guava | Bytes.lastIndexOf() method with Examples

Last Updated : 31 Jan, 2019

The lastIndexOf() method of Bytes Class in Guava library is used to find the last index of the given byte value in a byte array. This byte value to be searched and the byte array in which it is to be searched, both are passed as a parameter to this method. It returns an integer value which is the last index of the specified byte value. If the value is not found, it returns -1.

Syntax:

public static int lastIndexOf(byte[] array,
                              byte target)

Parameters: This method accepts two mandatory parameters:

array: which is the array of byte values in which the byte value is to searched.
target: which is byte value to be searched for last index in the byte array.

Return Value: This method returns an integer value which is the last index of the specified byte value. If the value is not found, it returns -1.

Below programs illustrates this method:

Example 1:

// Java code to show implementation of
// Guava's Bytes.lastIndexOf() method
  
import com.google.common.primitives.Bytes;
import java.util.Arrays;
  
class GFG {
  
    // Driver's code
    public static void main(String[] args)
    {
  
        // Creating a byte array
        byte[] arr = { 1, 2, 3, 4, 3, 5, 3, 4 };
  
        byte target = 3;
  
        // Using Bytes.lastIndexOf() method
        // to get the index of last appearance
        // of a given element in array
        // and return -1 if element is
        // not found in the array
        int index
            = Bytes.lastIndexOf(arr, target);
  
        if (index != -1) {
            System.out.println("Target is present"
                               + " at index "
                               + index);
        }
        else {
            System.out.println("Target is not present"
                               + " in the array");
        }
    }
}

Output:

Target is present at index 6

Example 2:

// Java code to show implementation of
// Guava's Bytes.lastIndexOf() method
  
import com.google.common.primitives.Bytes;
import java.util.Arrays;
  
class GFG {
  
    // Driver's code
    public static void main(String[] args)
    {
        // Creating a byte array
        byte[] arr = { 3, 5, 7, 11, 13 };
  
        byte target = 17;
  
        // Using Bytes.lastIndexOf() method
        // to get the index of last appearance
        // of a given element in array
        // and return -1 if element is
        // not found in the array
        int index
            = Bytes.lastIndexOf(arr, target);
  
        if (index != -1) {
            System.out.println("Target is present"
                               + " at index "
                               + index);
        }
        else {
            System.out.println("Target is not present"
                               + " in the array");
        }
    }
}

Output:

Target is not present in the array

Reference: https://google.github.io/guava/releases/19.0/api/docs/com/google/common/primitives/Bytes.html#lastIndexOf(byte[], %20byte)

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