Java Guava | Doubles.lastIndexOf() method with Examples

Last Updated : 31 Jan, 2019

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

Syntax:

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

Parameters: This method accepts two mandatory parameters:

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

Return Value: This method returns an integer value which is the last index of the specified double 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 Doubles.lastIndexOf() method 
  
import com.google.common.primitives.Doubles; 
import java.util.Arrays; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
  
        // Creating a double array 
        double[] arr = { 1.2, 2.2, 3.2, 4.2, 
                         3.2, 5.6, 3.2, 4.4 }; 
  
        double target = 3.2; 
  
        // Using Doubles.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 
            = Doubles.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 Doubles.lastIndexOf() method 
  
import com.google.common.primitives.Doubles; 
import java.util.Arrays; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
        // Creating a double array 
        double[] arr = { 1.2, 2.2, 3.2, 4.2, 
                         3.2, 5.6, 3.2, 4.4 }; 
  
        double target = 10.2; 
  
        // Using Doubles.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 
            = Doubles.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/Doubles.html#lastIndexOf(double[], %20double)

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready.

My Personal Notes

Related Articles