C# check if string is only number 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# how do you check if a string contains only digits
if (str.All(char.IsDigit)) {
Console.WriteLine("This string only contains numbers");
}