c check if string is numeric only code example
Example 1: c# check if string is all numbers
if (str.All(char.IsDigit)) {
// String only contains numbers
}
Example 2: c check if char is number
char c = 'a'; // or whatever
if (isalpha(c)) {
puts("it's a letter");
} else if (isdigit(c)) {
puts("it's a digit");
} else {
puts("something else?");
}