C＃数字格式：前导加号AND空格

Question

What I'm trying to do is to display numbers in a finance report like this:

+   5000
+    176
-  10000
- 620230

So I need to print out number that's 6 digits long, with leading sign.

I tried to combine leading sign with leading spaces like this: String.Format("{0,7:+#;-#;+0}", value); , but turns out it gives me:

   +5000
    +176
  -10000
 -620230

Is there anyway to use String.Format to get the output I want?

Edit : I understand that I could make my own format function to achieve that result, and I did use one. I'm asking out of curiosity with String.Format to see if it's could be done.

Answer 1

You need some trick to combine the parts (the sign and the number). Here is how it's done:

string.Format("{0:+;-;+}{0,7:#;#;0}",someNumber);

{0,7:#;#;0} will format the number so that only the absolute value is displayed. While the first part {0:+;-;+} will just display the sign accordingly to the value. You can make your own method to wrap that line of code as for convenience.

Answer 2

Here is a method that returns a formatted string. It's quite self explanatory.

static string FormatFinancialNumber(int number) {
    string sign = number < 0 ? "-" : "+"; // decide the sign
    return sign + Math.Abs(number).ToString().PadLeft(7); // Make the number part 7 characters long
}

Usage:

Console.WriteLine(FormatFinancialNumber(1));
Console.WriteLine(FormatFinancialNumber(-12));
Console.WriteLine(FormatFinancialNumber(123));
Console.WriteLine(FormatFinancialNumber(-1234));
Console.WriteLine(FormatFinancialNumber(12345));

Output:

+      1
-     12
+    123
-   1234
+  12345