This example demonstrate how to find specific items in array. We will use the org.apache.commons.lang.ArrayUtils class. This class provides method called contains(Object[] array, Object objectToFind) method to check if an array contains the objectToFind in it.
We can also use the indexOf(Object[] array, Object objectToFind) method and the lastIndexOf(Object[] array, Object objectToFind) method to get the index of an array element where our objectToFind is located.
package org.kodejava.example.commons.lang;
import org.apache.commons.lang.ArrayUtils;
public class ArrayUtilsIndexOfDemo {
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
Maven Dependencies
<!-- http://repo1.maven.org/maven2/commons-lang/commons-lang/2.6/commons-lang-2.6.jar -->
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.6</version>
</dependency>
Latest posts by Wayan (see all)
- How to format LocalDate object using Jackson? - February 16, 2017
- How to pretty print JSON string using Jackson? - February 15, 2017
- How to convert java.time.LocalDate to java.util.Date? - February 14, 2017