Expression-bodied definitions are the first “shortcut” for writing methods. They’re great for writing one-line methods, like this one:

bool IsEven(int num)
{
  return num % 2 == 0;
}

We can rewrite this definition as an expression-bodied definition by:

• removing the curly braces and return keyword, and
• adding the “fat arrow”, or =>, which is composed of the equal sign, =, and greater than, >, symbols

bool isEven(int num) => num % 2 == 0;

This also works for methods that return nothing, aka void:

void Shout(string x) => Console.WriteLine(x.ToUpper());

This type of definition can only be used when a method contains one expression. This helps us remember the name: expression-bodied definitions are method definitions with one expression.

Fun fact: some developers also call the fat arrow notation, =>, a squid! 🦑