Searching for an element in Vector with indexOf in Java

Vector has 4 ways to search for elements using the indexOf():

1) public int indexOf(Object obj): returns the index of the first occurrence of the object obj found in Vector.

2) public int indexOf(Object obj, int indiceDebut): returns the index of the first occurrence of the obj object found in Vector, starting the search from a leading index.

3) public int lastIndexOf(Object obj): returns the index of the last found occurrence of the obj object in Vector.

4) public int lastIndexOf(Object obj, int indiceDebut): returns the index of the first occurrence found of the obj object in Vector, looking backwards from a index start.

Example:

This example shows the use of the 4 methods mentioned and how they work:

import java.util.Collections; 
import java.util.Vector; 
public class indexOf {
 public static void main(String[] args) {

 //create vector
 Vector vector = new Vector(); 
 
 //add elements to vector
 vector.add("blue"); 
 vector.add("orange"); 
 vector.add("green"); 
 vector.add("black"); 
 vector.add("gray"); 
 vector.add("green"); 
 vector.add("yellow"); 
 vector.add("green"); 

 System.out.println(vector); 
 
 //returns the first occurrence
 int firstOcc = vector.indexOf("green"); 
 System.out.println("First occurrence of green"+
" in position: "+firstOcc); 
 
 //starts the search from the 3
 int index after Index = vector.indexOf("green", 3); 
 System.out.println("First occurrence of green"+
 " after index 2: "+afterIndex); 
 
 //returns the last occurrence
 int lastOcc = vector.lastIndexOf("green"); 
 System.out.println("Last occurrence of green"+
" in the position: "+lastOcc); 
 
 //starts the search backwards from the index 5
 int beforeIndex = vector.lastIndexOf("green", 6); 
 System.out.println("First occurrence of green"+
" before index 6: "+beforeIndex); 
 } 
}

Output:

[blue, orange, green, black, gray, green, yellow, green]
First occurrence of green in position: 2
First occurrence of green after index 2:  5
Last green occurrence in position: 7
First green occurrence before index 6: 5