Java Guava | Chars.lastIndexOf() method with Examples

The lastIndexOf() method of Chars Class in Guava library is used to find the last index of the given char value in a char array. This char value to be searched and the char 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 char value. If the value is not found, it returns -1.

Syntax:

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

Parameters: This method accepts two mandatory parameters:

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

Return Value: This method returns an integer value which is the last index of the specified char 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 Chars.lastIndexOf() method 
  
import com.google.common.primitives.Chars; 
import java.util.Arrays; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
  
        // Creating a char array 
        char[] arr = { 'a', 'b', 'c', 'd', 
                       'b', 'c', 'b', 'd' }; 
  
        char target = 'b'; 
  
        // Using Chars.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 
            = Chars.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 Chars.lastIndexOf() method 
  
import com.google.common.primitives.Chars; 
import java.util.Arrays; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
        // Creating a char array 
        char[] arr = { 'a', 'b', 'c', 'd', 
                       'b', 'c', 'b', 'd' }; 
  
        char target = 'z'; 
  
        // Using Chars.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 
            = Chars.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/18.0/api/docs/com/google/common/primitives/Chars.html#lastIndexOf(char[], %20char)

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