c# if string contains only numbers code example

Example 1: c# check if string is only letters and numbers

if (textVar.All(c => Char.IsLetterOrDigit(c))) {
    // String contains only letters & numbers
}

Example 2: if string contains number c#

"abc3def".Any(c => char.IsDigit(c));

// Or to make it shorter:
"abc3def".Any(char.IsDigit);