How do I calculate power-of in C#?

user_109251 0
Viewed 136552

I'm not that great with maths and C# doesn't seem to provide a power-of function so I was wondering if anyone knows how I would run a calculation like this:

var dimensions = ((100*100) / (100.00^3.00));
math c#
9 Answers

I'm answering this question because I don't find any answer why the ^ don't work for powers. The ^ operator in C# is an exclusive or operator shorten as XOR. The truth table of A ^ B shows that it outputs true whenever the inputs differ:

Input A Input B Output
0 0 0
0 1 1
1 0 1
1 1 0

Witch means that 100 ^ 3 does this calculation under the hood:

decimal   binary
    100 = 0110 0100 
      3 = 0000 0011
    ---   --------- ^
    103 = 0110 0111

With is of course not the same as Math.Pow(100, 3) with results to one million. You can use that or one of the other existing answers.

You could also shorten your code to this that gives the same result because C# respects the order of operations.

double dimensions = 100 * 100 / Math.Pow(100, 3); // == 0.01
user_45510410

Following is the code calculating power of decimal value for RaiseToPower for both -ve and +ve values. 

public decimal Power(decimal number, decimal raiseToPower)
        {
            decimal result = 0;
            if (raiseToPower < 0)
            {
                raiseToPower *= -1;
                result = 1 / number;
                for (int i = 1; i < raiseToPower; i++)
                {
                    result /= number;
                }
            }
            else
            {
                result = number;
                for (int i = 0; i <= raiseToPower; i++)
                {
                    result *= number;
                }
            }
            return result;
        }
user_121231360

For powers of 2:

var twoToThePowerOf = 1 << yourExponent;
// eg: 1 << 12 == 4096
user_15249130

Math.Pow() returns double so nice would be to write like this:

double d = Math.Pow(100.00, 3.00);
user_58849550 
static void Main(string[] args)
        {
            int i = 2;
            int n = -2;
            decimal y = 1;
            if (n > 0)
            {
                for (int x = 1; x <= n; x++)
                    y *= i;               
            }
            if (n < 0)
            {
                for (int x = -1; x >= n; x--)
                    y /= i;
            }
            Console.WriteLine(y);
        }
user_170657000
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