String interpolation provides a concise and convenient way to format strings. With string interpolation, you can embed expressions directly within a string literal, making your code more readable and reducing the need for complex string concatenation or formatting methods. In this blog, you’ll explore how to use string interpolation in C# and how it can simplify string formatting.

What is String Interpolation in C#?

String interpolation is a feature introduced in C# 6.0 that allows you to embed expressions directly within a string literal by prefixing the string with the $ symbol. Inside the string, you can include placeholders for expressions by enclosing them in curly braces {}. During runtime, these expressions are evaluated, and their values are inserted into the string.

Here’s an example that demonstrates string interpolation:

string name = "Alice";
int age = 30;
string message = $"Hello, {name}! You are {age} years old.";

In this example, the values of the name and age variables are interpolated into the string using the {} placeholders. The resulting message will be “Hello, Alice! You are 30 years old.”

Using Expressions

String interpolation allows you to include any valid C# expression inside the curly braces {}. This means you can perform calculations, call methods, or access properties within the interpolated expressions.

Here’s an example that demonstrates using expressions in string interpolation:

int x = 10;
int y = 5;
string result = $"The sum of {x} and {y} is {x + y}.";

In this example, the expression {x + y} calculates the sum of the variables x and y, which is then interpolated into the string.

Formatting Options

String interpolation also supports formatting options to control the appearance of interpolated values. You can apply formatting by adding a colon: followed by a format specifier, after the expression within the curly braces {}.

Here’s an example that demonstrates formatting in string interpolation:

double pi = Math.PI;
string formatted = $"The value of pi is {pi:F2}.";

In this example, the format specifier: F2 is used to format the pi value as a fixed-point number with two decimal places.

Benefits of String Interpolation

Using string interpolation offers several benefits:

  • Readability: String interpolation makes the code more readable and reduces the clutter of concatenation or formatting methods.
  • Simplicity: It simplifies string formatting by providing a concise syntax to embed expressions directly into the string.
  • Compile-time Checking: String interpolation expressions are checked for correctness during compilation, reducing the risk of runtime errors.


String interpolation is a powerful feature in C# that simplifies string formatting and improves code readability. You can create more concise and expressive code by leveraging the ability to embed expressions directly within a string literal. Consider using string interpolation in your C# projects to enhance the clarity and simplicity of your string formatting tasks.

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