Chapter 1: Introduction to Functions

In programming, a function serves as a reusable block of code that executes a specific task. The main purpose of using functions is to prevent the repetition of code that accomplishes the same goal multiple times. In the realm of object-oriented programming, functions are often referred to as methods. This article is part of my series on Dart Programming Tutorials.

To define a function in Dart, you can use the following syntax:

void raceHobbit() {

print("The Hobbits are peaceful");

}

You can invoke the function like this:

void main() {

raceHobbit();

}

The result will display: "The Hobbits are peaceful".

Functions can also be customized using parameters (commonly known as arguments). For example:

void raceHobbit(String hobbitName) {

print("The Hobbits are peaceful");

print("$hobbitName is a Hobbit");

}

You can then call it with:

void main() {

raceHobbit("Bilbo");

}

This will produce the output:

• "The Hobbits are peaceful"
• "Bilbo is a Hobbit".

In some cases, using more descriptive parameter names can enhance readability, especially in complex programs. The following example achieves the same output as above:

void raceHobbit({String hobbitName = ""}) {

print("The Hobbits are peaceful");

print("$hobbitName is a Hobbit");

}

void main() {

raceHobbit(hobbitName: "Bilbo");

}

You can also define functions with multiple parameters:

void raceHobbit(String race, String hobbitName) {

print("The $race are peaceful");

print("$hobbitName is a Hobbit");

}

void main() {

raceHobbit("Hobbits", "Bilbo");

}

The output remains consistent:

• "The Hobbits are peaceful"
• "Bilbo is a Hobbit".

Functions can also return values when required. For instance, let’s create a simple converter from pounds to kilograms:

double lbsToKilogram(double lbs) {

double kg = lbs * 0.453592;

print("$kg kg");

return kg;

}

void main() {

lbsToKilogram(200);

}

This will output: "90.7184 kg".

Stay tuned for our next tutorial, where we will delve into object-oriented programming in Dart.

May the code be with you,

-Arc