Why does Regex.IsMatch return wrong values? [duplicate]

Question

With this code, isMatch is false.

var input = "12312345023";
var isMatch = Regex.IsMatch(@"^\d{6,}", input);

And if input = "", isMatch is true. Not sure why it seems to be opposite of what it should be.

If I try the same pattern and input here it works as expected. But when I start a new console app with just that code, isMatch is not correct.

Fruchtzwerg · Accepted Answer · 2018-04-04 18:13:09Z

3

MSDN says:

public static bool IsMatch(
          string input,
          string pattern
)

Since your parameters are swapped, your pattern is empty. The result will always be true. You need to swap your parameters to get a correct result:

var isMatch = Regex.IsMatch(input, @"^\d{6,}");

answered Apr 4, 2018 at 18:13

Fruchtzwerg

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1 Comment

doh! of course! thanks