check if a string is only numbers c# code example
Example 1: c# how to check string is number
string s1 = "123";
string s2 = "abc";
bool isNumber = int.TryParse(s1, out int n); // returns true
isNumber = int.TryParse(s2, out int n); // returns false
Example 2: c# check if string is only letters and numbers
if (textVar.All(c => Char.IsLetterOrDigit(c))) {
// String contains only letters & numbers
}