String Formatting FAQ - C#

How do I show numbers with 5 fixed digits with leading zeroes

int _num1 = 123; 
int _num2 = 45; 
int _num3 = 123456; 
String.Format("{0:00000}", _num1); //"00123" 
String.Format("{0:00000}", _num2); //"00045" 
String.Format("{0:00000}", _num3); //"123456" 
String.Format("{0:d5}", _num1); //"00123" 
String.Format("{0:d5}", _num2); //"00045" 
String.Format("{0:d5}", _num3); //"123456" 

Can I substitute a string for a value? Yes:

String.Format("{0:yes;;no}", value)

This will print “no” if value is 0, “yes” if value is 1.

What’s the most efficient way to convert a type into a string?

Ans:

double testDouble = 19.95; 
String testString1 = String.Format("{0:C}", testDouble); // Boxing operation required. 
String testString2 = testDouble.ToString(”C”); // No boxing operation required. 

How can I format as percentage without having the number multiplied by 100?

Put a single quote (’) before the % in the format string.

myString.Format("{0:##.00′%", 1.23); 

This will yield “1.23%”.

Can I convert a number with a thousand separator to an int?

Ans: Yes - no matter what thousand separator is in use for your locale.

int x = int.Parse("1,345"); // fails int x = int.Parse("1,345",System.Globalization.NumberStyles.AllowThousands) 

This gives you an x of 1345.

How can I use curly brackets within a formatted number?

Ans: Yes - doubling them escapes them.
For example:

string.format("{{SomeString}}={0}","Hello"); 

will produce: “{SomeString}=Hellow”

How can I convert from currency back to a number?

Ans: You can add the bitmapped values of the Globalization.NumberStyles enumeration. // format double to currency

str = string.Format("{0:c}", pmt); // parse currency formatted string to double 
double.Parse(str, Globalization.NumberStyles.AllowCurrencySymbol + Globalization.NumberStyles.AllowDecimalPoint + Globalization.NumberStyles.AllowThousands); 

What’s a good way to format currency?

double val = 4219.6; str = string.Format("{0:$#,#.00;Call Us;Call Us}", val);

This will return “$4,219.60”. The .00 will force 2 decimals and the “;Call Us;Call Us” to show the text “Call Us” in place of negative and null values respectively. (Just in case)

How do I format an integer, with commas for thousands?

string str = string.Format("{0:#,0}", intValue); 

How can I format a phone number to look like 800.555.1212?

There’s no direct way to do this; however you can get dashes in the output.
So you can do this:

string tempStr = String.Format(”{0:###-###-####}”, 8005551212); string result =tempStr.Replace(’-',’.');