how to check if something is a char value in c++ code example

Example 1: how to check string contains char in c++

std::string s = "Hello";
if (s.find('e') != std::string::npos)
    cout << "Found";
else
    cout << "Not Found";

Example 2: check if character in string is digit c++

#include<stdio.h>
#include<ctype.h>

int main() {
   char val1 = 's';
   char val2 = '8';

   if(isdigit(val1))
   printf("The character is a digit\n");
   else
   printf("The character is not a digit\n");

   if(isdigit(val2))
   printf("The character is a digit\n");
   else
   printf("The character is not a digit");

   return 0;
}