String functions overview in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to get the length of the string.

C++

#include <iostream>
#include <string>

int main() {
    std::string text = "Hello";
    std::cout << text.[1]() << std::endl;
    return 0;
}

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

AgetSize

Bsize

Ccount

Dlength

Attempts:

3 left

💡 Hint

Common Mistakes

Using a function that doesn't exist like count() or getSize()

The length() function returns the number of characters in the string.

2fill in blank

medium

Complete the code to convert the string to uppercase using a loop.

C++

#include <iostream>
#include <string>
#include <cctype>

int main() {
    std::string text = "hello";
    for (int i = 0; i < text.length(); ++i) {
        text[i] = [1](text[i]);
    }
    std::cout << text << std::endl;
    return 0;
}

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Atoupper

BtoUpperCase

Cupper

Dtouppercase

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent functions like toUpperCase or upper

The toupper() function converts a character to uppercase.

3fill in blank

hard

Fix the error in the code to find the position of a character in the string.

C++

#include <iostream>
#include <string>

int main() {
    std::string text = "apple";
    size_t pos = text.[1]('p');
    std::cout << pos << std::endl;
    return 0;
}

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Afind

BindexOf

Csearch

Dposition

Attempts:

3 left

💡 Hint

Common Mistakes

Using JavaScript-like functions such as indexOf

The find() function returns the index of the first occurrence of the character.

4fill in blank

hard

Fill both blanks to create a substring from index 1 to 3.

C++

#include <iostream>
#include <string>

int main() {
    std::string text = "banana";
    std::string part = text.[1]([2], 3);
    std::cout << part << std::endl;
    return 0;
}

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Asubstr

Bsubstring

C1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using substring which is not a C++ string function

Wrong starting index

The substr() function extracts a substring starting at the given index. Here, starting at index 1 for length 3 gives "ana".

5fill in blank

hard

Fill all three blanks to replace 'cat' with 'dog' in the string.

C++

#include <iostream>
#include <string>

int main() {
    std::string text = "the cat sat";
    size_t pos = text.[1]("cat");
    if (pos != std::string::npos) {
        text.[2](pos, [3], "dog");
    }
    std::cout << text << std::endl;
    return 0;
}

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Afind

Breplace

C3

Derase

Attempts:

3 left

💡 Hint

Common Mistakes

Using erase instead of replace

Wrong length for replacement

First, find() locates "cat". Then replace() replaces 3 characters starting at that position with "dog".