What are some useful string utility functions in C++?

What are some useful string utility functions in C++?

In C++, the standard library provides several string utility functions. Some of the most useful ones include:

1. std::string::length() - Returns the length of the string.
2. std::string::substr() - Extracts a substring from the string.
3. std::string::find() - Searches for a substring and returns its position.
4. std::string::replace() - Replaces part of the string with another string.
5. std::string::append() - Adds characters to the end of the string.

Can you give an example of using substr()?

Sure! Here's an example:

std::string str = "Hello, World!";
std::string sub = str.substr(7, 5); // Extracts 'World'

This code takes the substring starting at index 7 with a length of 5.

What about the find() function?

The find() function is used to locate a substring within a string. For example:

std::string str = "Hello, World!";
size_t pos = str.find("World"); // pos will be 7

If the substring is found, it returns the starting index; otherwise, it returns std::string::npos.

Are there any performance considerations when using these functions?

Yes, performance can vary. Functions like find() may have linear complexity in the worst case, while substr() is generally efficient. It's best to use them judiciously, especially in performance-critical applications.