String Format for Int [C#]
Integer numbers can be formatted in .NET in many ways. You can use static method String.Format or instance method int.ToString. Following examples show how to align numbers (with spaces or zeroes), how to format negative numbers or how to do custom formatting like phone numbers.
Add zeroes before number
To add zeroes before a number, use colon separator „:“ and write as many zeroes as you want.
[C#]String.Format("{0:00000}", 15); // "00015" String.Format("{0:00000}", -15); // "-00015"
Align number to the right or left
To align number to the right, use comma „,“ followed by a number of characters. This alignment option must be before the colon separator.
[C#]String.Format("{0,5}", 15); // " 15" String.Format("{0,-5}", 15); // "15 " String.Format("{0,5:000}", 15); // " 015" String.Format("{0,-5:000}", 15); // "015 "
Different formatting for negative numbers and zero
You can have special format for negative numbers and zero. Use semicolon separator „;“ to separate formatting to two or three sections. The second section is format for negative numbers, the third section is for zero.
[C#]String.Format("{0:#;minus #}", 15); // "15" String.Format("{0:#;minus #}", -15); // "minus 15" String.Format("{0:#;minus #;zero}", 0); // "zero"
Custom number formatting (e.g. phone number)
Numbers can be formatted also to any custom format, e.g. like phone numbers or serial numbers.
[C#]String.Format("{0:+### ### ### ###}", 447900123456); // "+447 900 123 456" String.Format("{0:##-####-####}", 8958712551); // "89-5871-2551"
See also
- [C#] String Format for Double – format float numbers
- [C#] String Format for DateTime – format date and time
- [C#] IFormatProvider for Numbers – parse float numbers with IFormatProvider
- [C#] Custom IFormatProvider – string formatting with custom IFormatProvider
- [C#] Align String with Spaces – how to align text to the right or left
- [C#] Indent String with Spaces – how to indent text with repeated spaces
- MSDN Examples – MSDN examples for custom numeric formatting
Tips
- [C#] List Examples – illustrative examples of all List<T> methods
- [C#] Foreach Examples – how foreach and IEnumerable works debuggable online
- [C#] Switch Examples – switch statement examples debuggable online
- [C#] Using Statement Examples – using statement and IDisposable debuggable online