c++98 check if character is integer

To check if a character is an integer in C++98, you can use the isdigit() function from the <cctype> library. Here are the step-by-step explanations for using this function:

1. Include the <cctype> library: cpp #include <cctype>

2. Declare a character variable to store the character you want to check, for example, char ch = '7';.

3. Use the isdigit() function to check if the character is an integer: cpp if (isdigit(ch)) { // The character is an integer } else { // The character is not an integer }

The isdigit() function returns a non-zero value if the character is a decimal digit (0-9), and 0 otherwise.

Here's a complete example:

#include <iostream>
#include <cctype>

int main() {
    char ch = '7';

    if (isdigit(ch)) {
        std::cout << "The character is an integer." << std::endl;
    } else {
        std::cout << "The character is not an integer." << std::endl;
    }

    return 0;
}

In this example, the character '7' is an integer, so the output will be "The character is an integer."

Remember to include the <cctype> library and use the isdigit() function to check if a character is an integer in C++98.