Using sets to find A-Za-z plus the # and - chars ..?

Alan Kilborn

@Andrew-McP said in Using sets to find A-Za-z plus the # and - chars ..?:

I really admire you guys for figuring out Regular Expressions

So if someone says they have “figured out regular expressions”, I pity them. Because it just means they are ripe for an upcoming whipping when a regex misunderstanding of theirs really embarrasses them. :-)

It pays to always be humble when discussing regular expressions with others. :-)

I bet you never get lost

GPS!

I like the trick of having - as last character before ]

Not so much a trick, as a logical place to put it when you realize that anywhere except the first or last position it must form some sort of “range”.

Andrew McP

@Alan-Kilborn hahahah yes no way would I bet my house on any regular expression I recommend covering all, no matter how perverse, eventualities…

guy038

Hello, @peterjones,

In my previous post, I forgot to mention the ^ character, which has a special meaning within a Character class !

So, here is an updated version of my previous post :

If we consider the following CHARACTER CLASS structure :

[.......]
123456789

The POSSIBLE location(s), in order to find the LITERAL character below, are :

LITERAL Character [    :     POSSIBLE at any position, BETWEEN 2 to 8 
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character
							 
LITERAL Character ]    :     POSSIBLE at position 2 ONLY
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character
							 
LITERAL Character -    :     POSSIBLE at position 2
                             POSSIBLE at position 8
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character

LITERAL character ^    :     POSSIBLE at any position, BETWEEN 3 and 8
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character

							 
LITERAL Character \    :     POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character

And I suppose that @alan-kilborn could add :

To use a “literal ^” in a character class: Use it directly like any other character, e.g. [ab^c], but right after the opening [ of the class notation ; “escaping” is not necessary (but is permissible), e.g. [ab\^c]

Best Regards,

guy038