CODEWITHSUNDEEP
regexspacesalphanumericvariable-length
user3772697
user3772697

Reputation: 1

RegEx - 1 to 10 Alphanumeric Spaces Okay

New to Regular Expressions. Thanks in advance!

Need to validate field is 1-10 mixed-case alphanumeric and spaces are allowed. First character must be alphanumeric, not space.

Good Examples:

"Larry King"

"L King1"

"1larryking"

"L"

Bad Example:

" LarryKing"

This is what I have and it does work as long as the data is exactly 10 characters. The problem is that it does not allow less than 10 characters.

[0-9a-zA-Z][0-9a-zA-Z ][0-9a-zA-Z ][0-9a-zA-Z ][0-9a-zA-Z ][0-9a-zA-Z ][0-9a-zA-Z ][0-9a-zA-Z ][0-9a-zA-Z ][0-9a-zA-Z ]

I've read and tried many different things but am just not getting it.

Thank you,

Justin

Upvotes: 0

Views: 2347

Answers (7)

VinyJones
VinyJones

Reputation: 1014

i think the simplest way is to go with \w[\s\w]{0,9}

Note that \w is for [A-Za-z0-9_] so replace it by [A-Za-z0-9] if you don't want _ Note that \s is for any white char so replace it by if you don't want the others

Upvotes: 0

Casimir et Hippolyte
Casimir et Hippolyte

Reputation: 89557

I assume that the space is not allowed at the end too.

^[a-zA-Z0-9](?:[a-zA-Z0-9 ]{0,8}[a-zA-Z0-9])?$

or with posix character classes:

^[[:alnum:]](?:[[:alnum:] ]{0,8}[[:alnum:]])?$

Upvotes: 0

bukart
bukart

Reputation: 4906

I don't know what environment you are using and what engine. So I assume PCRE (typically for PHP)

this small regex does exact what you want: ^(?i)(?!\s)[a-z\d ]{1,10}$

What's going on?!

  • the ^ marks the start of the string (delete it, if the expression must not match the whole string)
  • the (?i) tells the engine to be case insensitive, so there's no need to write all letter lower and upper case in the expression later
  • the (?!\s) ensures the following char won't be a white space (\s) (it's a so called negative lookahead)
  • the [a-z\d ]{1,10} matches any letter (a-z), any digit (\d) and spaces () in a row with min 1 and max 10 occurances ({1,10})
  • the $ at the end marks the end of the string (delete it, if the expression must not match the whole string)

Here's also a small visualization for better understanding.

Regular expression visualization

Debuggex Demo

Upvotes: 1

tenub
tenub

Reputation: 3446

The below is probably most semantically correct:

(?=^[0-9a-zA-Z])(?=.*[0-9a-zA-Z]$)^[0-9a-zA-Z ]{1,10}$

It asserts that the first and last characters are alphanumeric and that the entire string is 1 to 10 characters in length (including spaces).

Upvotes: 0

Iriael
Iriael

Reputation: 1

Try this: ^[(^\s)a-zA-Z0-9][a-z0-9A-Z ]*

Not a space and alphanumeric for the first character, and then zero or more alphanumeric characters. It won't cap at 10 characters but it will work for any set of 1-10 characters.

Upvotes: 0

Minutiae
Minutiae

Reputation: 151

You want something like this.

[a-zA-Z0-9][a-zA-Z0-9 ]{0,9}

This first part ensures that it is alphanumeric. The second part gets your alphanumeric with a space. the {0,9} allows from anywhere from 0 to 9 occurrences of the second part. This will give your 1-10

Upvotes: 0

Lucas Trzesniewski
Lucas Trzesniewski

Reputation: 51330

Try this: [0-9a-zA-Z][0-9a-zA-Z ]{0,9}

The {x,y} syntax means between x and y times inclusive. {x,} means at least x times.

Upvotes: 0

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