I've never understood regular expressions [RESOLVED]

rebelwarlock · Dec 9, 2010

So I want to use preg_match() to detect a valid international number. The use of parenthesis and hyphens should be valid, but not mandatory. Basically, I want to throw up an error if the user enters anything other than digits, hyphens, or parenthesis. Any thoughts?

seadave77 · Dec 9, 2010

Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems. - Jamie Zawinski

That's what I think when I hear regular expressions. I don't know it well enough to give you one off the top of my head but here is a site that helps me when I have to use them. It's got a regex tester as well as some guides on how to make them.

http://regexlib.com/RETester.aspx

psionic98 · Dec 9, 2010

Also check this out

PHP Regular Expressions

was thinking it should work something like [a-zA-Z0-9\-\(\)]

I haven't done php in a while, but that statement should be any lower or upper case letters, any numbers, the minus sign(hyphen) or open/close parens..please don't quote me though!

johan851 · Dec 9, 2010

Regular expressions are the shiz.

Basically, I want to throw up an error if the user enters anything other than digits, hyphens, or parenthesis. Any thoughts?

if input matches [0-9\-\(\)]+
// it's all good
else
// it is not so good

psionic98 · Dec 9, 2010

I was close.. added in the alpha by mistake and forgot the +

rebelwarlock · Dec 9, 2010

johan851 said:
Regular expressions are the shiz.

if input does't match [0-9\-\(\)]+
// it's all good
else
// it is not so good

Yup, that did it! It's been about two years since I've had to do PHP (or any coding, really). Teaching made me slow. Thanks for the links too, they're going to help since I've been asked to work on form validation.

Ninth · Dec 11, 2010

Two nights ago, a misplaced wildcard in a regex in a script I was writing almost wiped out a .git repository.

/am terrified by regexes, especially in scripts ><

petteyg359 · Dec 14, 2010

See http://regexlib.com/

johan851 said:
[0-9\-\(\)]+

Not entirely concise.

Inside brackets, parentheses normally have no special function.
To match a hyphen in a bracketed set, just put it at the end.
To match all digits, use \d.

[\d()-]+ is equivalent.

I've never understood regular expressions [RESOLVED]

rebelwarlock

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psionic98

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johan851

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Ninth

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