Common string operations - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to copy the string from source to destination.

C

#include <string.h>
#include <stdio.h>

int main() {
    char source[] = "Hello";
    char destination[10];
    [1](destination, source);
    printf("%s\n", destination);
    return 0;
}

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Astrcpy

Bstrlen

Cstrcmp

Dstrcat

Attempts:

3 left

💡 Hint

Common Mistakes

Using strlen instead of strcpy will cause errors because strlen returns length, not copy.

Using strcmp compares strings but does not copy.

Using strcat appends strings instead of copying.

The function strcpy copies the content of the source string into the destination string.

2fill in blank

medium

Complete the code to find the length of the string text.

C

#include <string.h>
#include <stdio.h>

int main() {
    char text[] = "Programming";
    int length = [1](text);
    printf("Length: %d\n", length);
    return 0;
}

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Astrcpy

Bstrcat

Cstrcmp

Dstrlen

Attempts:

3 left

💡 Hint

Common Mistakes

Using strcpy will copy strings but not give length.

Using strcmp compares strings but does not give length.

Using strcat concatenates strings but does not give length.

The function strlen returns the number of characters in the string, excluding the null terminator.

3fill in blank

hard

Fix the error in the code to compare two strings str1 and str2.

C

#include <string.h>
#include <stdio.h>

int main() {
    char str1[] = "apple";
    char str2[] = "orange";
    if ([1](str1, str2) == 0) {
        printf("Strings are equal\n");
    } else {
        printf("Strings are different\n");
    }
    return 0;
}

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Astrlen

Bstrcmp

Cstrcpy

Dstrcat

Attempts:

3 left

💡 Hint

Common Mistakes

Using strcpy copies strings but does not compare.

Using strlen returns length, not comparison result.

Using strcat concatenates strings, not compares.

The function strcmp compares two strings and returns 0 if they are equal.

4fill in blank

hard

Fill both blanks to concatenate suffix to base and print the result.

C

#include <string.h>
#include <stdio.h>

int main() {
    char base[20] = "file";
    char suffix[] = ".txt";
    [1](base, suffix);
    printf("%s\n", [2]);
    return 0;
}

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Astrcat

Bstrcpy

Cbase

Dsuffix

Attempts:

3 left

💡 Hint

Common Mistakes

Using strcpy instead of strcat will overwrite base.

Printing suffix instead of base will not show the combined string.

strcat appends suffix to base. Then printing base shows the combined string.

5fill in blank

hard

Fill all three blanks to create a new string result that contains the uppercase version of word and print its length.

C

#include <stdio.h>
#include <string.h>
#include <ctype.h>

int main() {
    char word[] = "hello";
    char result[10];
    for (int i = 0; i < strlen(word); i++) {
        result[i] = [1](word[i]);
    }
    result[strlen(word)] = '\0';
    printf("%s\n", [2]);
    printf("Length: %d\n", [3](result));
    return 0;
}

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Atoupper

Bresult

Cstrlen

Dtolower

Attempts:

3 left

💡 Hint

Common Mistakes

Using tolower will convert letters to lowercase, not uppercase.

Printing word instead of result will show the original string.

Using strlen on word instead of result will not reflect changes.

toupper converts each character to uppercase. We print the result string and then its length using strlen.