1. Dart
  2. Functions in Dart
  3. Functions in Dart

Basics of Functions in Dart
 

Definition

A function in Dart is a block of code that performs a specific task. It's a reusable piece of code that can be called from other parts of your program.

Advantages of Using Functions

  • Code Reusability: Write once, use multiple times.
  • Modularity: Break down complex problems into simpler pieces.
  • Maintainability: Easier to update and manage code.
  • Readability: Makes the program easier to understand.

Use Cases

  • Performing calculations
  • Handling repetitive tasks
  • Managing data processing
  • Interacting with user input

Syntax

returnType functionName(parameters) {
  // function body   // return statement }
  • returnType: Specifies the type of value returned by the function. Use void if there is no return value.
  • functionName: The name of the function.
  • parameters: Optional. Values you can pass into the function.

Example Programs

Example 1: Simple Function

 

void greet() {
  print('Hello, World!');
}

void main() {
  greet(); // Calling the function }

Example 2: Function with Parameters

 

int add(int a, int b) {
  return a + b;
}

void main() {
  int sum = add(5, 3);
  print('Sum: $sum');
}

Example 3: Function with Optional Parameters

 

void printInfo(String name, [int? age]) {
  print('Name: $name');
  if (age != null) {
    print('Age: $age');
  }
}

void main() {
  printInfo('Alice');
  printInfo('Bob', 25);
}

Example 4: Arrow Functions

 

int multiply(int a, int b) => a * b;

void main() {
  print('Product: ${multiply(4, 5)}');
}

Conclusion

Functions are a fundamental part of Dart programming, enabling you to write clean and efficient code. With the ability to pass parameters and return values, functions provide flexibility and power in building applications.

Previous
Next