* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
1.8 KiB
id, title, challengeType, forumTopicId, dashedName
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
587d7db6367417b2b2512b9b | Find Characters with Lazy Matching | 1 | 301341 | find-characters-with-lazy-matching |
--description--
In regular expressions, a greedy match finds the longest possible part of a string that fits the regex pattern and returns it as a match. The alternative is called a lazy match, which finds the smallest possible part of the string that satisfies the regex pattern.
You can apply the regex /t[a-z]*i/
to the string "titanic"
. This regex is basically a pattern that starts with t
, ends with i
, and has some letters in between.
Regular expressions are by default greedy, so the match would return ["titani"]
. It finds the largest sub-string possible to fit the pattern.
However, you can use the ?
character to change it to lazy matching. "titanic"
matched against the adjusted regex of /t[a-z]*?i/
returns ["ti"]
.
Note
Parsing HTML with regular expressions should be avoided, but pattern matching an HTML string with regular expressions is completely fine.
--instructions--
Fix the regex /<.*>/
to return the HTML tag <h1>
and not the text "<h1>Winter is coming</h1>"
. Remember the wildcard .
in a regular expression matches any character.
--hints--
The result
variable should be an array with <h1>
in it
assert(result[0] == '<h1>');
myRegex
should use lazy matching
assert(/\?/g.test(myRegex));
myRegex
should not include the string 'h1'
assert(!myRegex.source.match('h1'));
--seed--
--seed-contents--
let text = "<h1>Winter is coming</h1>";
let myRegex = /<.*>/; // Change this line
let result = text.match(myRegex);
--solutions--
let text = "<h1>Winter is coming</h1>";
let myRegex = /<.*?>/; // Change this line
let result = text.match(myRegex);