Why command line arguments are used - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access the first command line argument.

C

#include <stdio.h>
int main(int argc, char *argv[]) {
    printf("First argument: %s\n", argv[[1]]);
    return 0;
}

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

A0

Bargc

C1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using argv[0] instead of argv[1] to get the first argument.

The first command line argument is stored at argv[1]. argv[0] is the program name.

2fill in blank

medium

Complete the code to check if at least one command line argument is provided.

C

#include <stdio.h>
int main(int argc, char *argv[]) {
    if (argc [1] 1) {
        printf("Argument provided\n");
    } else {
        printf("No argument provided\n");
    }
    return 0;
}

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

A<

B>

C==

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Checking if argc == 1 to find arguments, which is incorrect.

We check if argc > 1 because argc counts the program name plus arguments.

3fill in blank

hard

Fix the error in the code to print all command line arguments.

C

#include <stdio.h>
int main(int argc, char *argv[]) {
    for (int i = 1; i [1] argc; i++) {
        printf("Argument %d: %s\n", i, argv[i]);
    }
    return 0;
}

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

A<

B>

C>=

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= in the loop condition causing out-of-bounds access.

The loop should run while i < argc because argv[argc] is NULL and out of bounds.

4fill in blank

hard

Fill both blanks to create a program that prints the number of arguments excluding the program name.

C

#include <stdio.h>
int main(int argc, char *argv[]) {
    int count = argc [1] 1;
    printf("Number of arguments: %d\n", [2]);
    return 0;
}

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

A-

Bcount

Cargc

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Printing argc directly without subtracting 1.

Subtract 1 from argc to exclude the program name, then print count.

5fill in blank

hard

Fill all three blanks to create a program that prints each argument and its length.

C

#include <stdio.h>
#include <string.h>
int main(int argc, char *argv[]) {
    for (int i = 1; i [1] argc; i++) {
        printf("Argument: %[2], Length: %d\n", argv[i], [3](argv[i]));
    }
    return 0;
}

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

A<

Bs

Cstrlen

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= in the loop causing out-of-bounds errors.

Using wrong format specifier for string.

The loop runs while i < argc. Use %s to print strings and strlen to get the length.