Named Parameters

Part of the Fundamentals section of Coddy's Dart journey — lesson 73 of 94.

Named parameters in Dart allow you to specify function parameters by name rather than position. They're defined using curly braces {} in the function declaration.

Create a function with named parameters:

void greet({String name, int age}) {
  print('Hello, $name! You are $age years old.');
}

void main() {
  greet(name: 'Dart', age: 12);
}

After executing the above code, the output will be:

Hello, Dart! You are 12 years old.

When calling a function with named parameters, you specify the parameter name followed by a colon:

void main() {
  // Parameters can be in any order
  greet(age: 30, name: 'Alice');
}

After executing the above code, the output will be:

Hello, Alice! You are 30 years old.

Challenge

Beginner

In this challenge, you'll practice using named parameters in Dart. Named parameters make function calls more readable by specifying parameter names when calling a function.

Complete the greetUser function by adding named parameters for name and age. Then call the function with the provided values.

Expected output:

Hello, Alice! You are 25 years old.

Cheat sheet

Named parameters in Dart are defined using curly braces {} and allow you to specify function parameters by name rather than position:

void greet({String name, int age}) {
  print('Hello, $name! You are $age years old.');
}

When calling a function with named parameters, specify the parameter name followed by a colon. Parameters can be in any order:

greet(name: 'Dart', age: 12);
greet(age: 30, name: 'Alice');

Try it yourself

void main() {
  // These values are already defined for you
  String userName = 'Alice';
  int userAge = 25;
  
  // TODO: Call the greetUser function with named parameters
  // Pass userName as the name parameter and userAge as the age parameter
  
  
  // The function is defined below
}

// TODO: Modify this function to use named parameters instead of positional parameters
// Hint: Use curly braces {} around the parameters
void greetUser({required String name, required int age}) {
  print('Hello, $name! You are $age years old.');
}