Read-only arrays in Typescript - Mini Project: Build & Apply

Working with Read-only Arrays in TypeScript

📖 Scenario: Imagine you are managing a list of favorite fruits that should not be changed accidentally in your program. You want to make sure this list stays the same throughout your code.

🎯 Goal: You will create a read-only array of fruits, then try to work with it safely without changing the original list.

📋 What You'll Learn

Create a read-only array of strings with exact fruits

Create a variable to hold the number of fruits

Use a for loop to list all fruits

Print the list of fruits

💡 Why This Matters

🌍 Real World

Read-only arrays help protect important lists of data from accidental changes, like a fixed menu or a list of constants.

💼 Career

Understanding read-only arrays is useful for writing safer TypeScript code in jobs that require data integrity and immutability.

1

Create a read-only array of fruits

Create a read-only array called fruits with these exact values: 'apple', 'banana', 'cherry', 'date'.

Typescript

# Your code here

Need a hint?

Use readonly string[] to make the array read-only.

2

Create a variable for the number of fruits

Create a variable called count and set it to the length of the fruits array.

Typescript

const fruits: readonly string[] = ['apple', 'banana', 'cherry', 'date'];
# Your code here

Need a hint?

Use the length property of the array.

3

Use a for loop to list all fruits

Use a for loop with variable i from 0 to count - 1 to access each fruit in fruits.

Typescript

const fruits: readonly string[] = ['apple', 'banana', 'cherry', 'date'];
const count = fruits.length;
# Your code here

Need a hint?

Use a classic for loop to go through the array by index.

4

Print the list of fruits

Print the entire fruits array using console.log.

Typescript

const fruits: readonly string[] = ['apple', 'banana', 'cherry', 'date'];
const count = fruits.length;
for (let i = 0; i < count; i++) {
    console.log(fruits[i]);
}
# Your code here

Need a hint?

Use console.log(fruits) to print the whole array.