This weeks Regex Tuesday challenge, the first challenge, is to make a regex which finds and highlights repeated words in a body of text. It is a fairly easy challenge, and future challenges will usually be trickier.

You should just wrap the repeated word in a <strong> element. For example, this is is a test should be turned into this is <strong>is</strong> a test .

To test a regular expression on the test cases below, type it into the text input. Each test case will be marked as passed or failed respectively - you are aiming to get as many test cases as you can to pass. Note that JavaScript must be enabled for this feature to work. The regex engine used is the JavaScript regex engine; it is similar to PCRE, but with a few differences.

Test cases ( 0 /11) Permalink Hide passing tests

This is a test This is a test This is is a test This is <strong>is</strong> a test This test test is is This test <strong>test</strong> is <strong>is</strong> This test is a test This test is a test This this test is a test This <strong>this</strong> test is a test cat dog dog cat dog cat dog <strong>dog</strong> cat dog This test is a test tester This test is a test tester hello world hello world hello world hello world This nottest test is something This nottest test is something This is IS a test This is <strong>IS</strong> a test <Mack> I'll I'll be be back back in in a a bit bit. <Mack> I'll <strong>I'll</strong> be <strong>be</strong> back <strong>back</strong> in <strong>in</strong> a <strong>a</strong> bit <strong>bit</strong>.

Congratulations, your regex passes all the test cases! Remember to share this challenge.