Question

How to check if a string contains only digits using RegEx in C++

Answer 1

#include <iostream>
#include <regex>

bool containsOnlyDigits(const std::string& str) {
    std::regex digitRegex("^[0-9]*$");
    
    return std::regex_match(str, digitRegex);
}

int main() {
    std::string str = "123456";
    
    if (containsOnlyDigits(str)) {
        std::cout << "The string contains only digits." << std::endl;
    } else {
        std::cout << "The string does not contain only digits." << std::endl;
    }
}


 
/*
run:
 
The string contains only digits.
 
*/

 

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