RegEx Match Sequence of 5 characters

Question

I would like a c# regex to determine if a string contains 5+ characters within a defined sequence.

Example: If the sequence was the alphabet then 'ghijk' would be true, while 'lmn' would be false.

Edit: The sequence needs to be in order. from example above 'ghijz' would return false.

Answer 1

[a-zA-Z]{5,}

Answer 2

You don't necessarily need a regular expression to accomplish this:

bool IsInSequence(string str, string sequence)
{
    return str != null && str.Length >= 5 && sequence.Contains(str);
}

Unless I'm missing what you're trying to accomplish here.

Answer 3

Use Contains() instead of a RegEx:

string sequence = "abcdef"
bool match = ("abcdefghijklmnopqrstuvwxyz".contains(sequence) 
                                     && sequence.Length >= 5);

You're better off without a regex for what you're doing.

Answer 4

If the sequence needs to be in order, then what you're looking for can't be accomplished with regular expressions. Regular expressions can only perform pattern matching on characters, and can't place meaning (such as an ordering) on the sequence.