Array Declaration and Initialization in DSA C - Build from Scratch

Array Declaration and Initialization

📖 Scenario: You are working on a simple program that stores the ages of five friends. You want to keep these ages in an array so you can use them later for calculations or display.

🎯 Goal: Create an array to hold the ages of five friends, set a variable for the number of friends, then print all the ages in order.

📋 What You'll Learn

Declare an integer array called ages with exactly 5 elements

Initialize the ages array with the values 21, 25, 19, 30, and 22 in that order

Create an integer variable called num_friends and set it to 5

Use a for loop with the variable i to iterate from 0 to num_friends - 1

Print each age followed by a space on the same line

💡 Why This Matters

🌍 Real World

Arrays are used to store lists of data like scores, ages, or measurements in many programs.

💼 Career

Understanding arrays is essential for programming jobs because they are a basic way to organize and access multiple values efficiently.

1

Declare and initialize the array

Declare an integer array called ages with 5 elements and initialize it with these exact values: 21, 25, 19, 30, 22.

DSA C

# Declare and initialize the array ages with 5 values
// Your code here

Hint

Use the syntax int arrayName[size] = {values}; to declare and initialize an array in C.

2

Set the number of friends

Create an integer variable called num_friends and set it to 5.

DSA C

int ages[5] = {21, 25, 19, 30, 22};
// Declare num_friends and set it to 5
// Your code here

Hint

Use int num_friends = 5; to create and set the variable.

3

Loop through the array

Use a for loop with the variable i to iterate from 0 to num_friends - 1.

DSA C

int ages[5] = {21, 25, 19, 30, 22};
int num_friends = 5;
// Use a for loop with i from 0 to num_friends - 1
// Your code here

Hint

Use for (int i = 0; i < num_friends; i++) to loop through the array indices.

4

Print the ages

Inside the for loop, print each age from the ages array followed by a space. After the loop, print a newline character.

DSA C

int ages[5] = {21, 25, 19, 30, 22};
int num_friends = 5;
for (int i = 0; i < num_friends; i++) {
    // Print each age followed by a space
    // Your code here
}
// Print a newline character
// Your code here

Hint

Use printf("%d ", ages[i]); inside the loop and printf("\n"); after the loop.