CODEWITHSUNDEEP
regexc++11
Vorac
Vorac

Reputation: 9114

Regex replacement in C++11

I need to replace a string of the type T1.9 with the string unit19. The number of digits could vary e.g.T34.999 should become unit34999. Here is my progress:

std::regex e ("^(T\d+\.\d+)$");
std::string result (std::regex_replace(version, e, "") );

What should I write for format? Or is the approach to replace the string in one, no two, iterations, wrong?

Upvotes: 2

Views: 162

Answers (1)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626923

You need to adjust the capturing groups in the pattern and use backreferences in the replacement pattern:

^T([0-9]+)[.]([0-9]+)$

and replace with unit$1$2.

See the regex demo

A test at IDEONE:

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

int main() {
    std::vector<std::string> strings;
    strings.push_back("T34.999");
    strings.push_back("T1.9");
    std::regex reg("^T([0-9]+)[.]([0-9]+)$");
    for (size_t k = 0; k < strings.size(); k++)
    {
        std::cout << std::regex_replace(strings[k], reg, "unit$1$2") << std::endl;
    }
    return 0;
}

Upvotes: 2

Related Questions