java examples
Home Java Examples Resources Java Interview Questions
Brainpower SEO

How to find items in an array?

This example demonstrate how to find items in array. We use the ArrayUtils class. This class provides method such as contains(Object[] array, Object objectToFind) to check if the array contains some value. We can also use the indexOf(Object[] array, Object objectToFind) and lastIndexOf(Object[] array, Object objectToFind) methods to gen the index of array where our object is located.

package com.javacoderanch.example.commons.lang;

import org.apache.commons.lang.ArrayUtils;

public class ArrayUtilsIndexOf {
    public static void main(String[] args) {
        String[] colours = {"Red", "Orange", "Yellow", "Green", "Blue"
                , "Violet", "Orange", "Blue"};
         * Does colours array contains the Blue colour? 
        boolean contains = ArrayUtils.contains(colours, "Blue");        
        System.out.println("Contains Blue? " + contains);
         * Can you tell me the index of each colour defined bellow? 
        int indexOfYellow = ArrayUtils.indexOf(colours, "Yellow");
        System.out.println("indexOfYellow = " + indexOfYellow);
        int indexOfOrange = ArrayUtils.indexOf(colours, "Orange");
        System.out.println("indexOfOrange = " + indexOfOrange);
        int lastIndexOfOrange = ArrayUtils.lastIndexOf(colours, "Orange");
        System.out.println("lastIndexOfOrange = " + lastIndexOfOrange);

Here are the result of the code above.

Contains Blue? true
indexOfYellow = 2
indexOfOrange = 1
lastIndexOfOrange = 6