freeCodeCamp/curriculum/challenges/chinese/02-javascript-algorithms-an.../regular-expressions/match-everything-but-letter...

2.3 KiB

id title challengeType forumTopicId dashedName
587d7db8367417b2b2512ba0 Match Everything But Letters and Numbers 1 301353 match-everything-but-letters-and-numbers

--description--

You've learned that you can use a shortcut to match alphanumerics [A-Za-z0-9_] using \w. A natural pattern you might want to search for is the opposite of alphanumerics.

You can search for the opposite of the \w with \W. Note, the opposite pattern uses a capital letter. This shortcut is the same as [^A-Za-z0-9_].

let shortHand = /\W/;
let numbers = "42%";
let sentence = "Coding!";
numbers.match(shortHand); // Returns ["%"]
sentence.match(shortHand); // Returns ["!"]

--instructions--

Use the shorthand character class \W to count the number of non-alphanumeric characters in various quotes and strings.

--hints--

Your regex should use the global flag.

assert(nonAlphabetRegex.global);

Your regex should find 6 non-alphanumeric characters in "The five boxing wizards jump quickly.".

assert(
  'The five boxing wizards jump quickly.'.match(nonAlphabetRegex).length == 6
);

Your regex should use the shorthand character to match characters which are non-alphanumeric.

assert(/\\W/.test(nonAlphabetRegex.source));

Your regex should find 8 non-alphanumeric characters in "Pack my box with five dozen liquor jugs."

assert(
  'Pack my box with five dozen liquor jugs.'.match(nonAlphabetRegex).length == 8
);

Your regex should find 6 non-alphanumeric characters in "How vexingly quick daft zebras jump!"

assert(
  'How vexingly quick daft zebras jump!'.match(nonAlphabetRegex).length == 6
);

Your regex should find 12 non-alphanumeric characters in "123 456 7890 ABC def GHI jkl MNO pqr STU vwx YZ."

assert(
  '123 456 7890 ABC def GHI jkl MNO pqr STU vwx YZ.'.match(nonAlphabetRegex)
    .length == 12
);

--seed--

--seed-contents--

let quoteSample = "The five boxing wizards jump quickly.";
let nonAlphabetRegex = /change/; // Change this line
let result = quoteSample.match(nonAlphabetRegex).length;

--solutions--

let quoteSample = "The five boxing wizards_jump quickly.";
let nonAlphabetRegex = /\W/g; // Change this line
let result = quoteSample.match(nonAlphabetRegex).length;