freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-an.../regular-expressions/match-all-numbers.english.md

2.2 KiB

id title challengeType forumTopicId
5d712346c441eddfaeb5bdef Match All Numbers 1 18181

Description

You've learned shortcuts for common string patterns like alphanumerics. Another common pattern is looking for just digits or numbers. The shortcut to look for digit characters is \d, with a lowercase d. This is equal to the character class [0-9], which looks for a single character of any number between zero and nine.

Instructions

Use the shorthand character class \d to count how many digits are in movie titles. Written out numbers ("six" instead of 6) do not count.

Tests

tests:
  - text: Your regex should use the shortcut character to match digit characters
    testString: assert(/\\d/.test(numRegex.source));
  - text: Your regex should use the global flag.
    testString: assert(numRegex.global);
  - text: Your regex should find 1 digit in <code>"9"</code>.
    testString: assert("9".match(numRegex).length == 1);
  - text: Your regex should find 2 digits in <code>"Catch 22"</code>.
    testString: assert("Catch 22".match(numRegex).length == 2);
  - text: Your regex should find 3 digits in <code>"101 Dalmatians"</code>.
    testString: assert("101 Dalmatians".match(numRegex).length == 3);
  - text: Your regex should find no digits in <code>"One, Two, Three"</code>.
    testString: assert("One, Two, Three".match(numRegex) == null);
  - text: Your regex should find 2 digits in <code>"21 Jump Street"</code>.
    testString: assert("21 Jump Street".match(numRegex).length == 2);
  - text: 'Your regex should find 4 digits in <code>"2001: A Space Odyssey"</code>.'
    testString: 'assert("2001: A Space Odyssey".match(numRegex).length == 4);'

Challenge Seed

let movieName = "2001: A Space Odyssey";
let numRegex = /change/; // Change this line
let result = movieName.match(numRegex).length;

Solution

let movieName = "2001: A Space Odyssey";
let numRegex = /\d/g; // Change this line
let result = movieName.match(numRegex).length;