Re^2: Lookahead assertion

When the engine sees that it should try again because of the /g, it steps one character past where last it tried.
This explains why the final . in BrowserUk’s solution is not strictly necessary

Indeed. The final '.' is not necessary with Perl's regex engine.

But many other regex libraries -- including some that claim to be Perl-compatible -- do not have this pragmatic deviation from the classical regular expression operation; hence it has become a habit with me to do this explicitly.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

Comment on Re^2: Lookahead assertion

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Re^3: Lookahead assertion by talexb (Chancellor) on Oct 17, 2013 at 11:39 UTC
Thanks for your reply .. and I checked, the final dot makes no difference in the result .. `DB<6> @w3 = ( $foo =~ /(?=(\d{3}))/g ); DB<7> x @w3 0 123 1 234 2 345 3 456 4 567 5 679 6 790 DB<8> @w3 = ( $foo =~ /(?=(\d{3}))./g ); DB<9> !7 x @w3 0 123 1 234 2 345 3 456 4 567 5 679 6 790` [download] Good to know. Alex / talexb / Toronto Thanks PJ. We owe you so much. Groklaw -- RIP -- 2003 to 2013.	[reply] [d/l]