Regular Expression for the given format - start and end with alphanumeric

Question

I need to validate building name in the below format (length is 1-50)

my regex for alphanumeric and specified characters check

     /^[a-zA-Z0-9\s\)\(\]\[\._-&]+$/

Its showing invalid expression but when i exclude & it works fine.

     /^[a-zA-Z0-9\s\)\(\]\[\._-]+$/

Actual Format

Building name should use Letters, Numbers, Underscore_, Hyphen-, Period., Square-brackets[], Parentheses() ,Ampersand &

It should not start and end with any special characters continuously

Valid:

Empire3 State&Building[A]
7Empire.State-Building(A)
Empire(State)_Building[A]12

Invalid:

@#$@$@building))
().-building2
$buildingseven[0]&.

i am struggling for 2nd format. how to check for continuous allowed special characters at first and last. Any help is very much appreciated.

how to check regex for these testcases name[], &name2, name4()? any help please — Shalini, Jan 07 '14 at 06:02

Qantas 94 Heavy · Accepted Answer · 2013-12-26T12:53:43.850

2

Escape the - character:

/^(?!\W.+\W$)[a-zA-Z0-9\s\)\(\]\[\._\-&]+$/

In a character class, the - character signifies a range of characters (e.g 1-9). Because the ASCII code for & is less than _, your regular expressions fails to parse correctly.

Also, to check that no special characters are at the beginning or end, use \W (a character other than a letter, digit or underscore) in a lookahead to check that both the start and the end are not "special characters". If you count an underscore as a special character, use [^A-Za-z0-9] instead of \W.

var validBuildingName = /^(?!\W.+\W$)[a-zA-Z0-9\s\)\(\]\[\._\-&]+$/;
validBuildingName.test('(example)'); // false
validBuildingName.test('(example'); // true
validBuildingName.test('example)'); // true
validBuildingName.test('example'); // true

edited Dec 26 '13 at 12:53

answered Dec 26 '13 at 12:38

Qantas 94 Heavy

15,750
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It works great.thanks. but Empire3 State&Building[A] this also invalid for above regex – Shalini Dec 26 '13 at 12:49
@Sha: that works for me: `/^(?!\W.+\W$)[a-zA-Z0-9\s\)\(\]\[\._\-&]+$/.test('Empire(State)_Building[A]')`. Does that return `true`? – Qantas 94 Heavy Dec 26 '13 at 12:51
sorry.its working.but i gave with whitespace Empire3 State&Building[A] [] - – Shalini Dec 26 '13 at 13:00
@Sha: if you want whitespace to work, just add a space to the character class, so it becomes `[a-zA-Z0-9\s\)\(\]\[\._\-& ]`. – Qantas 94 Heavy Dec 26 '13 at 13:01
name should not end with continous character after whitespace:( can you check on this 'building[12] ) &' – Shalini Dec 26 '13 at 13:06
see my invalid example i.e it should not accept even allowed special characters at the beginning n end. – Shalini Dec 27 '13 at 04:18

Regular Expression for the given format - start and end with alphanumeric

1 Answers1