C# Language Formatting numbers in strings


You can use a colon and the standard numeric format syntax to control how numbers are formatted.

var decimalValue = 120.5;

var asCurrency = $"It costs {decimalValue:C}";
// String value is "It costs $120.50" (depending on your local currency settings)

var withThreeDecimalPlaces = $"Exactly {decimalValue:F3}";
// String value is "Exactly 120.500"

var integerValue = 57;

var prefixedIfNecessary = $"{integerValue:D5}";
// String value is "00057"

Live Demo on .NET Fiddle