First clear solution for [old] Three Words by mozurin - javascript coding challenges

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First solution in Clear category for [old] Three Words by mozurin

"use strict";

var threeWords = data => /((^| )[a-z]+(?= |$)){3}/i.test(data);

June 25, 2018

Comments:

tsym88 on May 21, 2019, 5:02 a.m.
I'm having a hard time translating this one. Would you be so kind to break it down? This is what my mind is doing. . . start of string or blank word non-capturing group? or end of string? Maybe that means if word 3 times, but I don't understand the end.

mozurin on May 22, 2019, 4:38 a.m.
You are puzzled about regexp syntax, right? If so, this regex consists of the following structure: <ul> <li>`(...){3}` : Some pattern in parentheses (`...`) repeats 3 times. <ul> <li>`(^| )` : Start of string (`^`), or single blank space. This represents the start position of a word.</li> <li>`[a-z]+` : One or more consecutive alphabets. This represents a word this task defines.</li> <li>`(?= |$)` : Positive lookahead (`(?=...)`) of end of string (`$`) or single blank space. This represents the end position of a word.</li> </ul></li> </ul> I'm using positive lookahead here (in other words, while making sure that the pattern occures immediately, excludes that part from consumption of the match result) so that next pattern repetition can find this single blank space character as the start position of the next word (what `(^| )` expects). Without positive lookahead, I will need two or more blank space characters as separator of words.

tsym88 on May 24, 2019, 4:12 a.m.
Thank you so much! This introduced me lookarounds and the .test, while expanding my regex knowledge.

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