isDigit()
Analyse if a char is a digit (that is a number). Returns true if thisChar is a number. isDigit(thisChar)thisChar: variable. Allowed data types: char. true: if thisChar is a number.
if (isDigit(myChar)) { // tests if myChar is a digit
Serial.println("The character is a number");
}
else {
Serial.println("The character is not a number");
}