Constant values with const val in Kotlin - Mini Project: Build & Apply

Using Constant Values with const val in Kotlin

📖 Scenario: You are creating a simple program to calculate the area of a rectangle. To keep your code clean and easy to update, you want to use a constant value for the number of sides of a rectangle.

🎯 Goal: Learn how to declare and use constant values with const val in Kotlin by creating a constant for the number of sides of a rectangle and using it in a calculation.

📋 What You'll Learn

Declare a constant using const val

Use the constant in a calculation

Print the result

💡 Why This Matters

🌍 Real World

Constants are used in real-world programs to store values that should not change, like configuration settings, fixed measurements, or limits.

💼 Career

Understanding how to use constants helps you write safer and clearer code, which is important in software development jobs.

1

Create a constant for the number of sides

Write a const val named SIDES and set it to 4.

Kotlin

/* Your code here */

Need a hint?

Use const val to declare a constant value that does not change.

2

Create variables for length and width

Create two variables: length with value 5 and width with value 3.

Kotlin

const val SIDES = 4
/* Your code here */

Need a hint?

Use val to create variables that hold the rectangle's dimensions.

3

Calculate the area of the rectangle

Create a variable area and set it to the product of length and width.

Kotlin

const val SIDES = 4
val length = 5
val width = 3
/* Your code here */

Need a hint?

Multiply length and width to get the area.

4

Print the number of sides and the area

Print the text "A rectangle has " followed by the constant SIDES, then " sides and area " followed by the variable area.

Kotlin

const val SIDES = 4
val length = 5
val width = 3
val area = length * width
/* Your code here */

Need a hint?

Use println and string templates with $ to include variables in the output.