This method(comes under System.Collections namespace) is used to check whether a specified element is present is Stack or not. Internally this method checks for equality by calling the Object.Equals method. Also, it performs a linear search, therefore, this method is an O(n) operation, where n is Count.
Syntax:
public virtual bool Contains (object obj);
Here, obj is the object to locate in the Stack. The value can be null.
Return Value: It returns true, if obj is found in the Stack otherwise returns false.
Below programs illustrate the use of above-discussed method:
Example 1:
// C# code to illustrate the // Stack.Contains() Method using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating a Stack
Stack myStack = new Stack();
// Inserting the elements into the Stack
myStack.Push( "Geeks" );
myStack.Push( "Geeks Classes" );
myStack.Push( "Noida" );
myStack.Push( "Data Structures" );
myStack.Push( "GeeksforGeeks" );
// Checking whether the element is
// present in the Stack or not
// The function returns True if the
// element is present in the Stack,
// else returns False
Console.WriteLine(myStack.Contains( "GeeksforGeeks" ));
}
} |
Output:
True
Example 2:
// C# code to illustrate the // Stack.Contains() Method using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating a Stack
Stack myStack = new Stack();
// Inserting the elements
// into the Stack
myStack.Push(5);
myStack.Push(10);
myStack.Push(15);
myStack.Push(20);
myStack.Push(25);
// Checking whether the element is
// present in the Stack or not
// The function returns True if the
// element is present in the Stack, else
// returns False
Console.WriteLine(myStack.Contains(7));
}
} |
Output:
False
Reference: