Functions and Loops in Dart | Flutter Beginner Guide 2025

We learn about mastering functions and loops in Dart is essential. Functions help you organize the code, while loops make repetitive tasks easier. In this guide, you will learn how to use functions and loops in a beginner-friendly way.

What is the Function in Dart?

A function is a reusable block of code that performs a task. Instead of repeating code, you can call a function multiple times.

Basic Syntax:

returnType functionName(parameters) {
// write code here
return value;
}

Example Function

void printUser(String name) {
print("Hello, $name! Welcome to Dart.");
}

void main() {
       printUser("Alien");
       printUser("Bullet");
}

Types of Functions in Dart

Without parameters & return value

void sayHello() {
print("Hello Flutter!");
}

With parameters

void addNumbers(int a, int b) {
print("Sum: ${a + b}");
}

With parameters & return type

int square(int number) {
return number * number;
}

What is the Loop in Dart?

A loop repeats a block of code until a condition is met.

• For Loop

void main() {
      for (int i = 1; i <= 10; i++) {
              print("Count: $i");
      }
}

• While Loop

void main() {
         int n = 1;
         while (n <= 5) {
                   print("Number: $n");
                   n++;
           }
}

• Do-While Loop

void main() {
int x = 1;
do {
        print("Value: $x");
       x++;
} while (x <= 5);
}

• For-in Loop

void main() {
        List fruits = ["Apple", "Banana", "Mango"];
        for (var fruit in fruits) {
               print(fruit);
         }
}

FAQs about Functions and Loops in Dart

Conclusion:
Learn about functions and loops in Dart, if you want to become a Flutter App developer. Functions make your code clean and reusable. The while loops help to manage repetitive tasks. Let’s start practicing with small task.