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Java program to get the Index of the first occurrence of the specified item in Vector collection

Given a Vector collection, we have to get the Index of the first occurrence of the specified item.
Submitted by Nidhi, on May 21, 2022

Problem Solution:

In this program, we will create a Vector collection with string elements. Then we will get the index of the first occurrence of the specified item in Vector collection using the indexOf() method.

Program/Source Code:

The source code to get the Index of the first occurrence of a specified item in Vector collection is given below. The given program is compiled and executed successfully.

// Java program to get the Index of the first occurrence 
// of the specified item in Vector collection

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Vector < String > vec = new Vector < String > ();

    vec.add("CAR");
    vec.add("BUS");
    vec.add("BIKE");
    vec.add("BUS");
    vec.add("TRUCK");

    System.out.println("Index of first occurrence of item 'BUS' is: " + vec.indexOf("BUS"));
    System.out.println("Index of first occurrence of item 'TRAIN' is: " + vec.indexOf("TRAIN"));
  }
}

Output:

Index of first occurrence of item 'BUS' is: 1
Index of first occurrence of item 'TRAIN' is: -1

Explanation:

In the above program, we imported the "java.util.*" package to use the Vector class. Here, we created a public class Main.

The Main class contains a main() method. The main() method is the entry point for the program. And, created Vector collections vec and add elements to it. Then we get the index of the first occurrence of the specified item in Vector collection using the indexOf() method and printed the result.

The indexOf() method returns the index of the first occurrence of the specified item, otherwise, it returns -1.

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