How to check if a String contains any letter from a to z? [duplicate]

Answer 1

You could use RegEx:

Regex.IsMatch(hello, @"^[a-zA-Z]+$");

If you don't like that, you can use LINQ:

hello.All(Char.IsLetter);

Or, you can loop through the characters, and use isAlpha:

Char.IsLetter(character);

Answer 2

What about:

//true if it doesn't contain letters
bool result = hello.Any(x => !char.IsLetter(x));

Answer 3

Replace your for loop by this :

errorCounter = Regex.Matches(yourstring,@"[a-zA-Z]").Count;

Remember to use Regex class, you have to using System.Text.RegularExpressions; in your import

Answer 4

For a minimal change:

for(int i=0; i<str.Length; i++ )
   if(str[i] >= 'a' && str[i] <= 'z' || str[i] >= 'A' && str[i] <= 'Z')
      errorCount++;

You could use regular expressions, at least if speed is not an issue and you do not really need the actual exact count.

Answer 5

Use regular expression no need to convert it to char array

if(Regex.IsMatch("yourString",".*?[a-zA-Z].*?"))
{
errorCounter++;
}

Answer 6

You can look for regular expression

Regex.IsMatch(str, @"^[a-zA-Z]+$");