how to easily trim a str in c++
To easily trim a string in C++, you can use the std::string
class and the std::string::erase
and std::string::find_first_not_of
functions. Here are the steps to trim a string:
- Declare a string variable and assign the string you want to trim to it.
- Use the
std::string::find_first_not_of
function to find the first character in the string that is not a whitespace character. This function returns the position of the first character that doesn't match the specified characters (in this case, whitespace characters). - Use the
std::string::erase
function to remove the characters from the beginning of the string up to the position returned byfind_first_not_of
. - Use the
std::string::find_last_not_of
function to find the last character in the string that is not a whitespace character. This function returns the position of the last character that doesn't match the specified characters (in this case, whitespace characters). - Use the
std::string::erase
function again to remove the characters from the position returned byfind_last_not_of
to the end of the string.
Here is an example code snippet that demonstrates how to trim a string in C++:
#include <iostream>
#include <string>
int main() {
std::string str = " Trim this string ";
// Trim leading whitespace
str.erase(0, str.find_first_not_of(" "));
// Trim trailing whitespace
str.erase(str.find_last_not_of(" ") + 1);
std::cout << "Trimmed string: " << str << std::endl;
return 0;
}
This code trims the leading and trailing whitespace from the string " Trim this string " and outputs "Trim this string". The std::string::find_first_not_of
function is used to find the first character that is not a whitespace character, and the std::string::find_last_not_of
function is used to find the last character that is not a whitespace character. The std::string::erase
function is then used to remove the leading and trailing whitespace characters from the string.