Regular expression to limit number of characters to 10

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149

I am trying to write a regular expression that will only allow lowercase letters and up to 10 characters. What I have so far looks like this:

pattern: /^[a-z]{0,10}+$/ 

This does not work or compile. I had a working one that would just allow lowercase letters which was this:

pattern: /^[a-z]+$/ 

But I need to limit the number of characters to 10.

2009-10-30 12:08
by NoName
The {} and the + do the same thing (counting), thus they are redundant, hence the error - PhiLho 2009-10-30 12:36
You should drop the '+' from /^[a-z]{0,10}+$/. It should be /^[a-z]{0,10}$ - Rashmi Pandit 2009-10-30 12:37
Note that pattern ^[a-z]{0,10}+$ compiles on some languages and some of the notable ones are Java, Perl (5.10+), PHP, Ruby (1.9+). See this page for more detail - Jerry 2014-01-07 06:59


299

You can use curly braces to control the number of occurrences. For example, this means 0 to 10:

/^[a-z]{0,10}$/

The options are:

  • {3} Exactly 3 occurrences;
  • {6,} At least 6 occurrences;
  • {2,5} 2 to 5 occurrences.

See the regular expression reference.

Your expression had a + after the closing curly brace, hence the error.

2009-10-30 12:10
by cletus
In chrome dev tools with ember I had to ommit the beginning ^ to property match ONLY requests with a name like 1234 or 5678, and I had to include the $ sig - Devin G Rhode 2018-06-07 22:30


9

/^[a-z]{0,10}$/ should work. /^[a-z]{1,10}$/ if you want to match at least one character, like /^[a-z]+$/ does.

2009-10-30 12:12
by Joren


8

It might be beneficial to add greedy matching to the end of the string, so you can accept strings > than 10 and the regex will only return up to the first 10 chars. /^[a-z0-9]{0,10}$?/

2009-10-30 12:24
by jfarrell


6

It very much depend on the program you're using. Different programs (Emacs, vi, sed, and Perl) use slightly different regular expressions. In this case, I'd say that in the first pattern, the last "+" should be removed.

2009-10-30 12:11
by Diego Sevilla


5

grep '^[0-9]\{1,16\}' | wc -l

Gives the counts with exact match count with limit

2017-03-02 08:06
by user6911841
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