The contains(Object elem) method is used to test the existence of an element in a vector.
Following is the declaration for java.util.Vector.contains() method
public boolean contains(Object elem)
elem − This is an object as input.
true − It returns true if and only if the specified object is the same as a component in this vector.Otherwise it returns false.
ClassCastException − if the type of the specified element is incompatible with this collection (optional).
NullPointerException − if the specified element is null and this collection does not support null elements (optional).
The following example shows the usage of java.util.Vector.contains() method.
package com.tutorialspoint; import java.util.Vector; public class VectorDemo { public static void main(String[] args) { // create an empty Vector vec with an initial capacity of 4 Vector<Integer> vec = new Vector<Integer>(4); // use add() method to add elements in the vector vec.add(4); vec.add(3); vec.add(2); vec.add(1); // let us check the existence of number 4 in the vector System.out.println("Checking the existence of number 4 :- "+vec.contains(4)); } }
Let us compile and run the above program, this will produce the following result.The method call returns true as the number exists in the vector
Checking the existence of number 4 :- true