Question

I’m trying to print physical quantities from a decimal datatype with up to 6 decimal places. I want the thousands separator to show up, but only for numbers that are >= 10,000 (or <= -10,000).

For instance:

• 100 -> 100
• 1000 -> 1000
• 9999 -> 9999
• 10000 -> 10,000

I’ve been using this format, but it’s not quite right:

myNumber.ToString("#,##0.######");

Is there a trick to the format string to get the thousands separator to only show up if there are 5 or more digits to the left of the decimal place?

Answer 1

I don’t think there is any special trick, you’ll have to do

var result = myNumber >= 10000.0m || myNumber <= -10000.0m ? 
                 myNumber.ToString("#,##0.######") : 
                 myNumber.ToString("###0.######");