Math.Round vs String.Format

Question

I need double value to be rounded to 2 digits. What is preferrable?

String.Format(\"{0:0.00}\", 123.4567);      // \"123.46\"
Math.Round(123.4567, 2)                 


        

Answer 1

They are different functions, if you need the output to be displayed, use the first one (that also forces decimals to appear). You will avoid the overhead of the inevitable .ToString() that will occur if the variable is of type double.

Note that the second one rounds the number but if it's an integer result, you will get just the integer (ie: 7 vs 7.00)