freeCodeCamp/specify-exact-number-of-matches.english.md at 05f73ca40969366e11710053d403e241493a7b0c

Randell Dawson 05f73ca409 fix(curriculum): Convert blockquote elements to triple backtick syntax for JavaScript Algorithms and Data Structures (#35992 )

* fix: convert js algorithms and data structures

* fix: revert some blocks back to blockquote

* fix: reverted comparison code block to blockquotes

* fix: change js to json

Co-Authored-By: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>

* fix: convert various section to triple backticks

* fix: Make the formatting consistent for comparisons

2019-05-17 08:20:30 -05:00

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id, title, challengeType

id	title	challengeType
587d7db9367417b2b2512ba7	Specify Exact Number of Matches	1

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.

Tests

tests:
  - text: Your regex should use curly brackets.
    testString: assert(timRegex.source.match(/{.*?}/).length > 0, 'Your regex should use curly brackets.');
  - text: Your regex should not match <code>"Timber"</code>
    testString: assert(!timRegex.test("Timber"), 'Your regex should not match <code>"Timber"</code>');
  - text: Your regex should not match <code>"Timmber"</code>
    testString: assert(!timRegex.test("Timmber"), 'Your regex should not match <code>"Timmber"</code>');
  - text: Your regex should not match <code>"Timmmber"</code>
    testString: assert(!timRegex.test("Timmmber"), 'Your regex should not match <code>"Timmmber"</code>');
  - text: Your regex should match <code>"Timmmmber"</code>
    testString: assert(timRegex.test("Timmmmber"), 'Your regex should match <code>"Timmmmber"</code>');
  - text: Your regex should not match <code>"Timber"</code> with 30 <code>m</code>'s in it.
    testString: assert(!timRegex.test("Ti" + "m".repeat(30) + "ber"), 'Your regex should not match <code>"Timber"</code> with 30 <code>m</code>\'s in it.');

Challenge Seed

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

Solution

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

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