In this example we shall show you how to search elements in a Vector. The Vector API provides us with methods for such operations. To search elements in a Vector one should perform the following steps:
- Create a new Vector.
- Populate the vector with elements, with
add(E e)API method of Vector. - Invoke
contains(Object o)API method of Vector to check if an element exists in the Vector. The method returns true if this vector contains the specified element. - Invoke
indexOf(Object o)API method of Vector. The method returns the index of the first occurrence of the specified element in this vector, or -1 if this vector does not contain the element. - To get the index of the last occurance of the specified element in Vector use the
lastIndexOf(Object element)method instead,
as described in the code snippet below.
package com.javacodegeeks.snippets.core;
import java.util.Vector;
public class SearchElementsVector {
public static void main(String[] args) {
// Create a Vector and populate it with elements
Vector vector = new Vector();
vector.add("element_1");
vector.add("element_2");
vector.add("element_3");
vector.add("element_1");
/*
boolean contains(Object element) operation returns true
if the Vector contains the specified object, false otherwise.
*/
boolean found = vector.contains("element_2");
System.out.println("Found element_2 : " + found);
/*
int indexOf(Object element) operation returns the index of the
first occurance of the specified element in Vector or -1 if
the specific element is not found. To get the index of the last
occurance of the specified element in Vector use the
int lastIndexOf(Object element) operation instead.
*/
int index = vector.indexOf("element_3");
System.out.println("Found element_3 : " + (index == -1?false:true) + ", in position : " + index);
int lastIndex = vector.lastIndexOf("element_1");
System.out.println("Found element_1 : " + (lastIndex == -1?false:true) + ", in position : " + lastIndex);
}
}
Output:
Found element_2 : true
Found element_3 : true, in position : 2
Found element_1 : true, in position : 3
This was an example of how to search elements in a Vector in Java.
