php checking the format of a string

Question

I am trying to verify if a string is properly formatted. Below are a few of the formats that come through. These are just random typed items.

1abc.abc

ab2.abc

abc.abc.abt

aerj/adfa.tht

The before the . can be symbols alpha and numeric. After the . The check im trying to do is check the end of the string for the . followed by no more than 4 alpha characters. I believe this can be done with regex but I do not know where to start on it.

An invalid string is anything containing numbers, symbols or greater than 4 characters following the period

and or give a good example of a valid string and an invalid string — kalpaitch
– kalpaitch, Commented Oct 12, 2012 at 20:23
an invalid string is anything with symbols, numbers or longer than 4 characters following the . — James
– James, Commented Oct 12, 2012 at 20:24

Adam Plocher · Accepted Answer · 2012-10-12 20:27:16Z

3

Try this (match all alphanumeric/symbols, but no spaces):

^([\S]+)\.([A-Za-z]{0,4})$

Same, but with spaces matched:

^(.*?)+\.([A-Za-z]{0,4})$

More specifically:

if (preg_match("/^([\S]+)\.([A-Za-z]{0,4})$/", $yourStr) == 1) { }

edited Oct 12, 2012 at 20:27

answered Oct 12, 2012 at 20:21

Adam Plocher

14.3k6 gold badges51 silver badges83 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

slugonamission Over a year ago

. matches anything, not just alphanumeric.

Adam Plocher Over a year ago

He said symbols, alpha, and number. I guess it would match spaces too, though...

slugonamission Over a year ago

I'm an idiot and completely read over symbols by accident. Although yeah, matches spaces ;)

slugonamission Over a year ago

In which case, use \w (or \W, whichever is not whitespace).

James Over a year ago

There is still one issue. In the instance of "abc.abc.abt" it fails

|

Ωmega · Accepted Answer · 2012-10-12 20:39:04Z

1

You should go with regex pattern /\.[a-zA-Z]{0,4}$/

answered Oct 12, 2012 at 20:39

Ωmega

44k35 gold badges143 silver badges213 bronze badges

Collectives™ on Stack Overflow

php checking the format of a string

2 Answers 2

6 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related