Using String Format to show decimal up to 2 places

Question

I have got a price field to display which sometimes can be either 100 or 100.99 or 100.9, What I want is to display the price in 2 decimal places only if the decimals are entered for that price , for instance if its 100 so it should only show 100 not 100.00 and if the price is 100.2 it should display 100.20 similarly for 100.22 should be same . I googled and came across some examples but they didn't match exactly what i wanted :

// just two decimal places
String.Format("{0:0.00}", 123.4567);      // "123.46"
String.Format("{0:0.00}", 123.4);         // "123.40"
String.Format("{0:0.00}", 123.0);         // "123.00"

Answer 1

This is a common formatting floating number use case.

Unfortunately, all of the built-in one-letter format strings (eg. F, G, N) won't achieve this directly.
For example, num.ToString("F2") will always show 2 decimal places like 123.40.

You'll have to use 0.## pattern even it looks a little verbose.

A complete code example:

double a = 123.4567;
double b = 123.40;
double c = 123.00;

string sa = a.ToString("0.##"); // 123.46
string sb = b.ToString("0.##"); // 123.4
string sc = c.ToString("0.##"); // 123

Answer 2

I am afraid there is no built-in format that will do this. You will have to use a different format depending on whether the value is a whole number or not. Or always format to 2 decimal places, and manipulate the string afterwards to remove any trailing ".00".

Answer 3

Simple one line code :

public static string DoFormat(double myNumber)
{
    return string.Format("{0:0.00}", myNumber).Replace(".00","");
}