Chapter 16 - Worked Exercises 1

Exercise 1 - Recap

Part 0 - Terminology

Explain what is meant by the following terms in the context of strings:

• Copying

• Concatenating

• Truncating

• Finding

Part 1 - Copying

Write a function string_copy that returns a pointer to a dynamically allocated character array with the contents of the string original.

const char* string_copy(const char* original) {
   // ... 
}

Show how copying is achieved with the std::string class.

Part 2 - Concatenating

Write a function string_concatenate that returns a pointer to a dynamically allocated character array with the contents of first and second concatenated:

const char* string_concatenate(const char* first, const char* second) {
    // ...
};

Show how concatenation is achieved with the std::string class.

Part 3 - Truncating

Write a function string_truncate that returns a pointer to a dynamically allocated character array with the contents of original truncated to the range specified by integer parameters from and to.

The range copied should be [from, to), meaning inclusive of from but not inclusive of to.

const char* string_truncate(const char* original, int from, int to) {
   // ...
}

Show how truncating is achieved with the std::string class.

Exercise 2 - String Splitting

Write a function that splits a string representing a sentence, into a vector of strings each corresponding to a word in the sentence:

std::vector<std::string> splitString(std::string sentence) {
    // ...
}

Usage

int main() {
    std::cout << "Enter a sentence:" << std::endl;

    std::string sentence;
    std::getline(std::cin, sentence);

    std::vector<std::string> words = splitString(sentence);
    for (auto word: words) {
        std::cout << word << std::endl;
    }
}

Exercise 3 - Palindrome

Write a function to check if a given string is a palindrome or not.

A palindrome is a word, number, phrase, or other sequence of characters which reads the same backward as forward, such as madam, racecar.

bool palindrome(std::string word) {
    // ...
}

Exercise 4 - Word Manipulation

Part 1

Write a function that counts the number of vowels in a sentence.

int numVowels(std::string sentence);

Part 2

Write a function that converts every alternate character of a string into uppercase.

void toAltUpper(std::string& sentence);

Exercise 5

Write a program that displays the position of every occurrence of character 'a' in a string:

void displayAllAs(std::string sentence);

Example

Enter a sentence: 
Good day String! Today is beautiful!
      ^             ^       ^