Statement lambdas

Context: Statement lambdas have a block of statements inside braces {}. They can contain multiple statements, loops, conditionals, and even local variables.

Action<int> printSquare = x =>
{
    int square = x * x;
    Console.WriteLine($"Square of {x} is {square}");
};
printSquare(5);

With return value

Func<int, int, int> max = (a, b) =>
{
    if (a > b) return a;
    return b;
};

Use in LINQ (less common but possible)

var numbers = new List<int> { 1, 2, 3, 4 };
var evenSquares = numbers.Where(x => x % 2 == 0)
                         .Select(x =>
                         {
                             int square = x * x;
                             return square;
                         });

Real-world usage example

Complex event handlers: When an event handler needs multiple steps (logging, validation, processing), use a statement lambda.

Example: In WinForms, you can write button.Click += (s, e) => { MessageBox.Show("Hi"); LogClick(); };.

Related sections

• 7.3 Lambda expressions
• 7.3.1 Syntax