lang3

Find elements in an array

With this example we are going to demonstrate how to find elements in an array. We are using the org.apache.commons.lang3.ArrayUtils class, that provides operations on arrays, primitive arrays (like int[]) and primitive wrapper arrays (like Integer[]). In short, to find elements in an array you should:

  • Create a String array.
  • Use contains(Object[] array, Object objectToFind) method of ArrayUtils to check if the object is in the given array.
  • Use the indexOf(Object[] array, Object objectToFind) method find the index of the given object in the array.
  • Use the lastIndexOf(Object[] array, Object objectToFind) method to find the last index of the given object within the array.

Let’s take a look at the code snippet that follows:  

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package com.javacodegeeks.snippets.core;
  
import org.apache.commons.lang3.ArrayUtils;
 
public class FindIndexes {
     
    public static void main(String[] args) {
     
        String[] fruits = { "Orange", "Apple", "Blueberry", "Guava"
 
 
    , "Apple", "Peach", "Orange", "Strawberry" };
 
    
 
  // Check if fruits array contains Guava
 
  boolean contains = ArrayUtils.contains(fruits, "Guava");
  
 
  System.out.println("Contains Guava? Answer = " + contains);
 
    
 
  // Find the index of Blueberry
 
  int indexOfBlueberry = ArrayUtils.indexOf(fruits, "Blueberry");
 
  System.out.println("index of Blueberry = " + indexOfBlueberry);
  
 
  // Find the index of first Orange
 
  int indexOfOrange = ArrayUtils.indexOf(fruits, "Orange");
 
  System.out.println("index of Orange = " + indexOfOrange);
 
   
 
  // Find the last index of Orange
 
  int lastIndexOfOrange = ArrayUtils.lastIndexOf(fruits, "Orange");
 
  System.out.println("last index of Orange = " + lastIndexOfOrange);
    }
}

Output:

Contains Guava? Answer = true
index of Blueberry = 2
index of Orange = 0
last index of Orange = 6

  
This was an example of how to find elements in an array in Java.

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Byron Kiourtzoglou

Byron is a master software engineer working in the IT and Telecom domains. He is an applications developer in a wide variety of applications/services. He is currently acting as the team leader and technical architect for a proprietary service creation and integration platform for both the IT and Telecom industries in addition to a in-house big data real-time analytics solution. He is always fascinated by SOA, middleware services and mobile development. Byron is co-founder and Executive Editor at Java Code Geeks.
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