freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/regular-expressions/specify-exact-number-of-matches.md

id, title, challengeType, forumTopicId, dashedName

id	title	challengeType	forumTopicId	dashedName
587d7db9367417b2b2512ba7	Specify Exact Number of Matches	1	301365	specify-exact-number-of-matches

--description--

You can specify the lower and upper number of patterns with quantity specifiers using curly brackets. Sometimes you only want a specific number of matches.

To specify a certain number of patterns, just have that one number between the curly brackets.

For example, to match only the word "hah" with the letter a 3 times, your regex would be /ha{3}h/.

let A4 = "haaaah";
let A3 = "haaah";
let A100 = "h" + "a".repeat(100) + "h";
let multipleHA = /ha{3}h/;
multipleHA.test(A4); // Returns false
multipleHA.test(A3); // Returns true
multipleHA.test(A100); // Returns false

--instructions--

Change the regex timRegex to match the word "Timber" only when it has four letter m's.

--hints--

Your regex should use curly brackets.

assert(timRegex.source.match(/{.*?}/).length > 0);

Your regex should not match "Timber"

timRegex.lastIndex = 0;
assert(!timRegex.test('Timber'));

Your regex should not match "Timmber"

timRegex.lastIndex = 0;
assert(!timRegex.test('Timmber'));

Your regex should not match "Timmmber"

timRegex.lastIndex = 0;
assert(!timRegex.test('Timmmber'));

Your regex should match "Timmmmber"

timRegex.lastIndex = 0;
assert(timRegex.test('Timmmmber'));

Your regex should not match "Timber" with 30 m's in it.

timRegex.lastIndex = 0;
assert(!timRegex.test('Ti' + 'm'.repeat(30) + 'ber'));

--seed--

--seed-contents--

let timStr = "Timmmmber";
let timRegex = /change/; // Change this line
let result = timRegex.test(timStr);

--solutions--

let timStr = "Timmmmber";
let timRegex = /Tim{4}ber/; // Change this line
let result = timRegex.test(timStr);