How to check whether number is perfect square or not in C#

4 Answers

0 votes
// When a square root is a whole number, then the number is a perfect square number

using System;

public class Program
{
	private static bool isPerfectSquare(int number) {
		double d_sqrt = Math.Sqrt((double)number);
		int n = (int)d_sqrt;

		if (n == d_sqrt) {
			return true;
		}
		else {
			return false;
		}
	}
	
	public static void Main()
	{
		int num = 81;

		if (isPerfectSquare(num) != false) {
			Console.Write(num + " is a perfect square");
		}
		else {
			Console.Write(num + " is not a perfect square");
		}
	}
}







/*
run:
   
81 is a perfect square
   
*/

 



answered May 14, 2023 by avibootz
edited May 14, 2023 by avibootz
0 votes
// When a square root is a whole number, then the number is a perfect square number

using System;

public class Program
{
	private static bool isPerfectSquare(int number) {
		if (number >= 0) {
			double d_sqrt = Math.Sqrt((double)number);

			return d_sqrt * d_sqrt == number;
		}

		return false;
	}
	
	public static void Main()
	{
		int num = 81;

		if (isPerfectSquare(num) != false) {
			Console.Write(num + " is a perfect square");
		}
		else {
			Console.Write(num + " is not a perfect square");
		}
	}
}







/*
run:
   
81 is a perfect square
   
*/

 



answered May 14, 2023 by avibootz
edited May 14, 2023 by avibootz
0 votes
// When a square root is a whole number, then the number is a perfect square number

using System;

public class Program
{
	private static bool isPerfectSquare(int number) {
		double d_sqrt = Math.Sqrt((double)number);

		if ((int)Math.Pow((int)(d_sqrt + 0.5), 2) == number) {
			return true;
		}
		else {
			return false;
		}

	}
	
	public static void Main()
	{
		int num = 81;

		if (isPerfectSquare(num) != false) {
			Console.Write(num + " is a perfect square");
		}
		else {
			Console.Write(num + " is not a perfect square");
		}
	}
}







/*
run:
   
81 is a perfect square
   
*/

 



answered May 14, 2023 by avibootz
0 votes
// When a square root is a whole number, then the number is a perfect square number
 
using System;
 
public class Program
{
    private static bool isPerfectSquare(int number) {
        double sq = Math.Sqrt(number); 
        
        return ((sq - Math.Floor(sq)) == 0); 
    }
     
    public static void Main()
    {
        int num = 81;
 
        if (isPerfectSquare(num) != false) {
            Console.Write(num + " is a perfect square");
        }
        else {
            Console.Write(num + " is not a perfect square");
        }
    }
}
 
 
 
/*
run:
    
81 is a perfect square
    
*/

 



answered Sep 16, 2025 by avibootz
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