How to Efficiently Replace Text within a String in C ?

Finding and Replacing Text in a Standard String

In various programming scenarios, it becomes essential to manipulate strings by replacing specific characters or substrings. For standard strings in C , there are effective methods for performing search-and-replace operations.

Using the std::replace Function

The std::replace function provides a straightforward way to replace occurrences of a substring within a string. The syntax of std::replace is as follows:

std::string& replace(std::size_t pos, std::size_t n, const std::string& str);

Here, pos represents the starting position, n indicates the number of characters to replace, and str is the replacement string.

Example:

Consider the following string:

std::string s("One hello, two hellos.");

To replace all instances of "hello" with "world", you can use the following code:

s.replace(s.find("hello"), s.find("hello") + 5, "world"); // Find the position of "hello", replace 5 characters (length of "hello") with "world"

Using boost::replace_all

The Boost library provides a more convenient option for performing find-and-replace operations with its boost::replace_all function. It takes a string, a string to find, and a string to replace with.

Example:

To replace all occurrences of "foo" with "bar" in the following string:

std::string target("Would you like a foo of chocolate. Two foos of chocolate?");

Using boost::replace_all, you can do it as follows:

#include <boost/algorithm/string.hpp> // Include the Boost library

...

boost::replace_all(target, "foo", "bar");

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