Question

Write a short C++ function that removes all the punctuation from a string \(s\) storing a sentence. For example, this operation would transform the string "Let's try, Mike." to "Lets try Mike".

Short answer

The function `removePunctuation` iterates through each character and appends non-punctuation characters to a new string.

Step-by-step solution

- Include Necessary Headers

The first step in writing the C++ function is to include the necessary headers. In this case, we need to include the iostream and string libraries.

- Define the Function

Define the function with an appropriate name, for example, `removePunctuation`. The function should take a reference to a constant string as a parameter to avoid copying and to prevent modification of the original string.

- Create a New String

Within the function, create a new empty string to store the resulting text after punctuation removal.

- Loop Through the Original String

Create a `for` loop to iterate over each character in the original string. For each character, check if it is a punctuation mark using the `ispunct` function.

- Check and Append Characters

Inside the loop, if a character is not punctuation (i.e., `ispunct` returns false), append it to the new string.

- Return the Result

Finally, return the new string that contains the text without punctuation.

- Complete Function Code

The final function code in C++ is as follows: ```cpp#include #include #include std::string removePunctuation(const std::string& s) { std::string result; for (char c : s) { if (!ispunct(c)) { result += c; } } return result;}```

Key concepts

C++ functions

In C++, functions allow us to encapsulate code into reusable blocks.
A function consists of a return type, a name, parameters, and a body containing the executable code.
For instance, in the exercise, we define a function called `removePunctuation` which has the following components:

• **Return type:** The function returns a `std::string`.
• **Function name:** The name is `removePunctuation`.
• **Parameters:** It takes one parameter, a constant reference to a string, `const std::string& s`.
• **Function body:** The body contains the logic to remove punctuation from the input string.

Encapsulating code inside functions makes it easier to manage and debug, and promotes code reuse, improving the overall quality of the software. By defining `removePunctuation`, we have a specific, well-defined operation to remove punctuation from any given string, without modifying the original data.

string handling in C++

String handling in C++ is a common task that involves operations such as concatenation, comparison, and modification of strings.
The `std::string` class in C++ provides a convenient way to work with strings.
Here are some commonly used operations:

• **Concatenation:** Use the `+` or `+=` operator to join strings.
• **Accessing characters:** Use the `[]` operator or the `at` method to access individual characters.
• **Iteration:** Use a `for` loop to go through each character in a string.
• **Comparison:** Use the `compare` method or `==` operator to compare strings.

In the exercise, we utilize a string to create a new text without punctuation. We iterate over each character of the original string to check if it is punctuation and then decide whether to include it in the new string. This demonstrates the power and flexibility of `std::string` in handling and manipulating text.

punctuation removal in C++

Removing punctuation from a string in C++ can be efficiently done by using the `ispunct` function provided in the `` library.
The process typically involves:

• **Including necessary headers:** Ensure to include ``, ``, and ``.
• **Iterating through the string:** Use a loop to examine each character.
• **Checking for punctuation:** Apply the `ispunct` function to determine if a character is a punctuation mark.
• **Building a new string:** Append characters that are not punctuation to a new string.

The `removePunctuation` function works as follows:

 std::string removePunctuation(const std::string& s) { 
 std::string result; 
 for (char c : s) { 
 if (!ispunct(c)) { 
 result += c; 
 } 
 } 
 return result; 
 } 

This code loops through each character of the input string `s`, checks if it is punctuation using `ispunct`, and if it’s not, appends it to the `result` string.
Finally, it returns the `result` string which is the punctuation-free version of the input string.