CODEWITHSUNDEEP
regex
LRB
LRB

Reputation: 1639

RegEx to find two or more consecutive chars

I need to determine if a string contains two or more consecutive alpha chars. Two or more [a-zA-Z] side by side. Example:

"ab" -> valid
"a1" -> invalid
"a b" -> invalid
"a"-> invalid
"a ab" -> valid
"11" -> invalid

Upvotes: 162

Views: 172469

Answers (4)

Mc Kazou
Mc Kazou

Reputation: 71

Personally I've used:

[0-9][0-9]+.

But the answer from Simon, is way better.

Upvotes: 7

James Anderson
James Anderson

Reputation: 191

[a-zA-Z]{2,} does not work for two or more identical consecutive characters. To do that, you should capture any character and then repeat the capture like this:

(.)\1

The parenthesis captures the . which represents any character and \1 is the result of the capture - basically looking for a consecutive repeat of that character. If you wish to be specific on what characters you wish to find are identical consecutive, just replace the "any character" with a character class...

([a-zA-Z])\1

Finds a consecutive repeating lower or upper case letter. Matches on abbc123 and not abc1223. To allow for a space between them (i.e. a ab), then include an optional space in the regex between the captured character and the repeat...

([a-z]A-Z])\s?\1

Upvotes: 18

Kevin
Kevin

Reputation: 465

I'm pretty sure you can just use [A-z] instead of the [a-zA-Z] to get small and upper case alpha chars http://www.w3schools.com/jsref/jsref_obj_regexp.asp

Upvotes: -7

Simon
Simon

Reputation: 32873

This should do the trick:

[a-zA-Z]{2,}

Upvotes: 335

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