Coding Exercise 18: Using C-style Strings

Create a program that determines the length of a first name and last name individually and then the length of the entire name through the use of the C-style string functions strlen, strcpy, strcat.

Begin by decalring and initializing the C-style string variable first_name to contain "Bjarne".

Now, declare and initialize a second C-style string variable last_name to contain "Stroustrup".

Yout must also declare a third C-style string variable whole_name but do not initialize it yet.

Remember that the variable whole_name must be large enough to contain the first and last name with no whitespaces.

Now, by using the C-style string function strlen, declare and initialize the variable first_name_length to contain the length of the first_name string and the variable last_name_length to contain the length of the last_name string.

Using the C-style string function strcpy, copy the first_name string into the whole_name string variable.

Now, by using the C-style string function strcat, concatenate the last_name string at the end of the whole_name string.

Finally, by using the C-style string function strlen, declare and initialize the variable whole_name_length to contain the length of the whole_name string.

#include <iostream>
#include <cstring>
using namespace std;

void strings_and_functions() {

    //----WRITE YOUR CODE BELOW THIS LINE----
    
    // Initialization
    char first_name[50] {"Bjarne"};
    char last_name[50] {"Stroustrup"};
    char whole_name[50];

    size_t first_name_length = strlen(first_name);
    size_t last_name_length = strlen(last_name);

    strcpy(whole_name, first_name);
    // strcat(whole_name, " ");
    strcat(whole_name, last_name);
    size_t whole_name_length = strlen(whole_name);

    //----WRITE YOUR CODE ABOVE THIS LINE----
    //----DO NOT MODIFY THE CODE BELOW THIS LINE----
    
    cout << "The length of the first name, " << first_name << ", is " << first_name_length << " letters long and the length of the last name, " << last_name << ", is " << last_name_length << " letters long. This means that the length of the whole name must be " << whole_name_length << " letters long.";
}

Coding Exercise 19: Using C++ Strings - Exercise 1

Create a program that will be used to regormat a name so that it can be read more easily.

The string variable unformatted_full_name is comprised of two substrings

• first_name
• last_name in that order. Each substring begins with a captial letter.

Begin by declaring and initializing the string variable first_name from the string variable unformatted_full_name remembering that when initializing from another string the first integer within the curly brackets represents the starting index of the substring you wish to copy and the second integer represents the length of the substring.

Next, declare and initialize the string variable last_name by using the assignment operator = and the string function substr on the string variable unformatted_full_name.

Next, declare and initialize the string variable formatted_full_name. This should be done through the use of the concatentation operator + by concatenating the string variables first_name and last_name in that order, and then assigning the concatenated string to formatted_full_name using the assignment operator =.

Now the string variable formatted_full_name contains the string "StephenHawking". We see taht the string is no more formatted than the original string vairable unformatted_full_name and that is because the addition operator + does not add whitespace between strings when concatenating them.

Fortunately, we can use the string function insert on the string variable formatted_full_name to insert a whitespace between the substrings such that formatted_full_name will then contain the string "Stephen Hawking".

#include <iostream>
#include <string>
using namespace std;

void cpp_strings() {
    
    string unformatted_full_name {"StephenHawking"};
    
    //----DO NOT MODIFY THE CODE ABOVE THIS LINE----
    //----WRITE YOUR CODE BELOW THIS LINE----
    
    string first_name {unformatted_full_name, 0, 7};
    string last_name = unformatted_full_name.substr(7, 7);

    string formatted_full_name = first_name + last_name;

    formatted_full_name.insert(7, " ");

    
    //----WRITE YOUR CODE ABOVE THIS LINE----
    //----DO NOT MODIFY THE CODE BELOW THIS LINE----
    
    cout << formatted_full_name;
}

Coding Exercise 19: Using C++ Strings - Exercise 2

Create a program that will be used in a digital library to format and sort journal entries based on the authors last name. Each entry has room to store only the last name of the author.

Begin by removing the first name "Issac" from the string variable journal_entry_1 by using the string function erase. Do not forget to also remove the whitespace so that the string variable journal_entry_1 will then contain the string "Newton" with no whitespaces.

The journal entries should be sorted alphabetically based on the authors last name. For example, the last name "Brown" should come before "Davis".

Create an if statement so that if the last name contained within journal_entry_2 is alphabetically less than the last name contained within journal_entyr_1, then the string values are swapped using the string function swap.

You may use either of the comparison operators < > in the if statement but remember that following ASCII, "A" is lexicographically lower than "B".

#include <iostream>
#include <string>
using namespace std;

void cpp_strings() {
    
    string journal_entry_1 {"Isaac Newton"};
    string journal_entry_2 {"Leibniz"};
    
    //----DO NOT MODIFY THE CODE ABOVE THIS LINE----
    //----WRITE YOUR CODE BELOW THIS LINE----
    
    journal_entry_1.erase(0, 6);

    if (journal_entry_1 > journal_entry_2) {
        journal_entry_1.swap (journal_entry_2);
    }

    
    //----WRITE YOUR CODE ABOVE THIS LINE----
    //----DO NOT MODIFY THE CODE BELOW THIS LINE----
    
    cout << journal_entry_1 << "\n" << journal_entry_2;
}