Index Of Element 

Apache Commons Lang 3.0 is a java library with lot of utilities and reusable components. This requires the library commons-lang3-3.0.1.jar to be in classpath. The following example shows using ArrayUtils.indexOf() API. It returns the index of element in the array if found, otherwise returns -1.

File Name  :   com/bethecoder/tutorials/commons_lang/tests/arrays/IndexOfTest.java  Author  :   Sudhakar KV Email  :   [email protected]

package com.bethecoder.tutorials.commons_lang.tests.arrays; import org.apache.commons.lang3.ArrayUtils; public class IndexOfTest {   /**    * @param args    */   public static void main(String[] args) {     String [] strings = { "TWO", "ONE", "TWO", "THREE", "TWO", "FOUR" };     int [] ints = { 1, 2, 3, 2, 4, 5, 6, 7, 2, 8 };     System.out.println(ArrayUtils.indexOf(strings, "TWO"));     System.out.println(ArrayUtils.indexOf(strings, "FIVE"));          System.out.println(ArrayUtils.indexOf(ints, 2));     System.out.println(ArrayUtils.indexOf(ints, 9));   } }

0
-1
1
-1