main function and program entry - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the main function in C.

C

int [1]() {
    return 0;
}

Drag options to blanks, or click blank then click option'

Amain

Bstart

Cbegin

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using a function name other than 'main' for the program entry point.

Forgetting to specify the return type as int.

The main function in C must be named main. This is where the program starts running.

2fill in blank

medium

Complete the code to print "Hello, World!" inside the main function.

C

#include <stdio.h>

int main() {
    [1]("Hello, World!\n");
    return 0;
}

Drag options to blanks, or click blank then click option'

Aprint

Bprintln

Cecho

Dprintf

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'print' which is not a C function.

Using 'echo' or 'println' which are not valid in C.

In C, printf is used to print formatted output to the screen.

3fill in blank

hard

Fix the error in the main function declaration to make it valid C code.

C

int [1](void) {
    return 0;
}

Drag options to blanks, or click blank then click option'

Aprogram

Bmain

Cstart

Dentry

Attempts:

3 left

💡 Hint

Common Mistakes

Using other function names like 'start' or 'entry' instead of 'main'.

The main function must be named main to be recognized as the program entry point.

4fill in blank

hard

Fill both blanks to complete the main function that prints a number.

C

#include <stdio.h>

int [1]() {
    int num = 5;
    [2]("Number: %d\n", num);
    return 0;
}

Drag options to blanks, or click blank then click option'

Amain

Bprint

Cprintf

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'print' instead of 'printf'.

Naming the function other than 'main'.

The program starts with the main function and uses printf to print formatted output.

5fill in blank

hard

Fill all three blanks to complete a main function that prints a message and returns success.

C

#include <stdio.h>

int [1]() {
    [2]("Welcome to C programming!\n");
    return [3];
}

Drag options to blanks, or click blank then click option'

Amain

Bprintf

C0

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Returning a non-zero value to indicate success.

Using a function name other than 'main'.

The main function is named 'main', uses 'printf' to print, and returns 0 to indicate success.