--- title: String Interpolation --- # String Interpolation In C#, typically to concatenate strings you would either use the “+” operator or composite formatting with a method such as String.Format. By composite formatting I am referring to a format string with indexed placeholders (format items) and a list of objects to be used in the placeholders. ## ``` string message = "Hello " + firstName + " " + lastName + "!"; string message2 = string.Format("Hello {0} {1}!", firstName, lastName); ``` With interpolated string expressions, you have a string with contained expressions that are replaced with the expressions’ results. You have to prefix your string literal with a dollar sign ($). The expressions you want included in the string are placed inline enclosed in curly braces. The above message would now look like this: ## ``` string message = $"Hello {firstName} {lastName}!"; ``` **Small Bit Of Useful Information** In string interpolation you have the ability to call functions, properties and ternary operators: ``` int a = 3; int b = 454; string result = $"{a}+{b} = {a+b}"; ```