Mastering Regular Expressions in JavaScript

Learn to use regular expressions in JavaScript with regex object methods (test, exec) and string methods (match, search, replace, split) through examples.

Explore the first JavaScript exercise by filtering a phone-number array to include only 801 area codes with a regular expression, using the browser and console logs.

Explore simple regular expressions to match numbers starting with 801- using a hyphen, and compare two implementations: array filter with regex test and a loop, to extract matching phone numbers.

Explore how to exclude characters with negated sets using the caret at the start, including ranges like 0-9 and A-F, and how to escape the caret.

Explore shorthand character sets in JavaScript regular expressions, including digits, word characters, whitespace, their negations, global flag, demonstrated with regex pal examples.

Explore repetition amounts in regex with curly braces after an item, using {min,max}, {n}, or {n,}, and apply to examples like three-letter words, hex numbers, and Social Security numbers.

Revisit greedy and lazy quantifiers in JavaScript regular expressions, applying repetition rules to match two digits, a hyphen, and four to six digits, and observe how laziness changes matches.

Learn to validate a phone number in JavaScript using an immediately invoked function expression, a regex literal with optional parts, and keyup to toggle green or red classes.

Learn how the caret and dollar sign anchor matches at the start and end of a line. Explore how global, ignore-case, and multi-line flags shape these anchored matches.

Develop accurate regular expressions by narrowing patterns with digit ranges and anchors, making matches like five-digit and four-digit zip codes precise, and using groups to handle optional parts.

Apply the string wrapper's replace method on a text variable to substitute any day of the week with Monday in content.js. Display the results on the console.

Learn about capturing groups in regular expressions, how parentheses capture text for later use, how to reference them, and non-capturing groups like (?:) with examples.

Learn that group back references refer to captured text, not the pattern, and see how HTML examples use capturing versus non-capturing groups to validate matches.

Discover negative lookahead groups in regular expressions, illustrated by password validation, and review lookahead concepts, capture groups, non-capturing groups, and the regex cheat sheet.

Explore how named capture groups help solve a problem by labeling groups as first and last, then accessing them with groups.first and groups.last in JavaScript.

Learn to extract all numbers from a string using the string match method with a global regex, convert them with parse int, and sum them with reduce.