How to determine if a string contains a sequence of repeated letters

Question

Using JavaScript, I need to check if a given string contains a sequence of repeated letters, like this:

\"aaaaa\"

How can I do t

Answer 1

Use regular expressions:

var hasDuplicates = (/([a-z])\1/i).test(str)

Or if you don't want to catch aA and the likes

var hasDuplicates = (/([a-zA-Z])\1/).test(str)

Or, if you've decided you want to clarify your question:

var hasDuplicates = (/^([a-zA-Z])\1+$/).test(str)