Auto storage class - Mini Project: Build & Apply

Understanding the Auto Storage Class in C

📖 Scenario: Imagine you are writing a small C program to understand how variables behave inside a function. You want to see how the auto storage class works by default for local variables.

🎯 Goal: You will create a simple C program that declares local variables with and without the auto keyword inside a function, assign values, and print them to observe their behavior.

📋 What You'll Learn

Declare local variables inside a function using the auto storage class explicitly and implicitly

Assign integer values to these variables

Print the values of these variables to the console

💡 Why This Matters

🌍 Real World

Understanding variable storage classes helps in managing memory and variable lifetime in C programs, which is important for writing efficient and bug-free code.

💼 Career

Knowledge of storage classes like <code>auto</code> is fundamental for C programmers, embedded systems developers, and anyone working with low-level programming.

1

Create the main function and declare a local variable

Write a main function and inside it declare an integer variable called num1 and assign it the value 10.

C

int main() {
    // Declare an integer variable num1 and assign 10
    // Your code here
    return 0;
}

Need a hint?

Remember, local variables inside functions are by default auto storage class.

2

Declare another local variable with the auto keyword

Inside the main function, declare another integer variable called num2 using the auto keyword and assign it the value 20.

C

int main() {
    int num1 = 10;
    // Declare an auto integer variable num2 and assign 20
    // Your code here
    return 0;
}

Need a hint?

The auto keyword is optional because local variables are auto by default, but you can write it explicitly.

3

Print the values of both variables

Use printf to print the values of num1 and num2 inside the main function. Use the format "num1 = %d\n" and "num2 = %d\n" respectively.

C

int main() {
    int num1 = 10;
    auto int num2 = 20;
    // Print num1 and num2 values
    // Your code here
    return 0;
}

Need a hint?

Include stdio.h at the top to use printf.

4

Run the program and observe the output

Run the program and observe the output. It should print the values of num1 and num2 on separate lines.

C

#include 

int main() {
    int num1 = 10;
    auto int num2 = 20;
    printf("num1 = %d\n", num1);
    printf("num2 = %d\n", num2);
    // Your code here
    return 0;
}

Need a hint?

The output shows that both variables hold their assigned values correctly.