Printing whole numbers with {#} in C#?

Question

I'm sorry if this is a duplicate but I haven't found anything relevant to it.

So, how can I print 0 for the numbers having a whole square root with the following code?

for (n = 1.0; n <= 10; n++) 
{
    Console.WriteLine ("Fractional Part : {0 :#.####}", (Math.Sqrt(n) - (int) Math.Sqrt(n)));
}

Current O/P:

Answer 1

Assuming a leading zero on the other fractional results is acceptable, and since your result is always in the range of [0,1), you could just change #.#### to 0.####.

for (var n = 1.0; n <= 10; n++)
{
    Console.WriteLine("Fractional Part : {0:0.####}", (Math.Sqrt(n) - (int) Math.Sqrt(n)));
}

Results:

Fractional Part : 0
Fractional Part : 0.4142
Fractional Part : 0.7321
Fractional Part : 0
Fractional Part : 0.2361

Answer 2

How about using The numeric "N" format specifier with 4 precision?

for (var n = 1.0; n <= 10; n++)
{
    Console.WriteLine("Fractional Part : {0}", 
                      (Math.Sqrt(n) - (int)Math.Sqrt(n)).ToString("N4"));
}

Result is:

Fractional Part : 0.0000
Fractional Part : 0.4142
Fractional Part : 0.7321
Fractional Part : 0.0000
Fractional Part : 0.2361
Fractional Part : 0.4495
Fractional Part : 0.6458
Fractional Part : 0.8284
Fractional Part : 0.0000
Fractional Part : 0.1623