indexOf() Method : Java.util.ArrayList

Declaration :

public int indexOf(Object obj)

1	public int indexOf(Object obj)

Explanation :

Purpose	Method returns the index of the first occurrence of the specified element in list
Parameters	obj ==> The element to search for
Return Value	Returns the index of the first occurrence of the specified element
Exception	NA

Example

The following example shows the usage of java.util.Arraylist.indexOf() method.

package com.c4learn.arraylist;
import java.util.ArrayList;
public class ArrayListExamples {
  public static void main(String args[]) {
    // Create ArrayList 1
    ArrayList<String> arrlist1 = new ArrayList<String>(5);
    // Fill Elements in ArrayList 1
    arrlist1.add("A");
    arrlist1.add("B");
    arrlist1.add("C");
    arrlist1.add("D");
    arrlist1.add("E");
    arrlist1.add("F");
      // Print Array List
    System.out.println("List Element : " + arrlist1);
    //Print Element's Position
    System.out.println("Index of Element E : " + arrlist1.indexOf("E"));
    System.out.println("Index of Element D : " + arrlist1.indexOf("D"));
    System.out.println("Index of Element F : " + arrlist1.indexOf("F"));
    System.out.println("Index of Element A : " + arrlist1.indexOf("A"));
  }
}

package com.c4learn.arraylist;

import java.util.ArrayList;

public class ArrayListExamples {

public static void main(String args[]) {

// Create ArrayList 1

ArrayList<String> arrlist1 = new ArrayList<String>(5);

// Fill Elements in ArrayList 1

arrlist1.add("A");

arrlist1.add("B");

arrlist1.add("C");

arrlist1.add("D");

arrlist1.add("E");

arrlist1.add("F");

// Print Array List

System.out.println("List Element : " + arrlist1);

//Print Element's Position

System.out.println("Index of Element E : " + arrlist1.indexOf("E"));

System.out.println("Index of Element D : " + arrlist1.indexOf("D"));

System.out.println("Index of Element F : " + arrlist1.indexOf("F"));

System.out.println("Index of Element A : " + arrlist1.indexOf("A"));

}

Output :

List Element : [A, B, C, D, E, F]
Index of Element E : 4
Index of Element D : 3
Index of Element F : 5
Index of Element A : 0

List Element : [A, B, C, D, E, F]

Index of Element E : 4

Index of Element D : 3

Index of Element F : 5

Index of Element A : 0