freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/regular-expressions/match-letters-of-the-alphabet.md

id, title, challengeType, forumTopicId

id	title	challengeType	forumTopicId
587d7db5367417b2b2512b96	Match Letters of the Alphabet	1	301354

Description

You saw how you can use character sets to specify a group of characters to match, but that's a lot of typing when you need to match a large range of characters (for example, every letter in the alphabet). Fortunately, there is a built-in feature that makes this short and simple. Inside a character set, you can define a range of characters to match using a hyphen character: -. For example, to match lowercase letters a through e you would use [a-e].

let catStr = "cat";
let batStr = "bat";
let matStr = "mat";
let bgRegex = /[a-e]at/;
catStr.match(bgRegex); // Returns ["cat"]
batStr.match(bgRegex); // Returns ["bat"]
matStr.match(bgRegex); // Returns null

Instructions

Match all the letters in the string quoteSample. Note
Be sure to match both upper- and lowercase letters.

Tests

tests:
  - text: Your regex <code>alphabetRegex</code> should match 35 items.
    testString: assert(result.length == 35);
  - text: Your regex <code>alphabetRegex</code> should use the global flag.
    testString: assert(alphabetRegex.flags.match(/g/).length == 1);
  - text: Your regex <code>alphabetRegex</code> should use the case insensitive flag.
    testString: assert(alphabetRegex.flags.match(/i/).length == 1);

Challenge Seed

let quoteSample = "The quick brown fox jumps over the lazy dog.";
let alphabetRegex = /change/; // Change this line
let result = alphabetRegex; // Change this line

Solution

let quoteSample = "The quick brown fox jumps over the lazy dog.";
let alphabetRegex = /[a-z]/gi; // Change this line
let result = quoteSample.match(alphabetRegex); // Change this line