Complete Regular Expressions Bootcamp - Go from Zero to Hero

Explore regular expression syntax by enclosing patterns in forward slashes. Learn to match characters like star and tree, and test patterns with a regex engine.

Explore literal character matching, the simplest regex pattern, which finds a single letter or group of characters in a test string and locates all occurrences left to right.

Explore regex modes and flags, including global and standard matches, case-insensitive searches, and single-line versus multi-line behavior to control search patterns.

Learn how metacharacters and other special characters control regex matching, distinguishing literal text from patterns, with examples using period, question mark, and parentheses.

Discover the 12 basic metacharacters with special meanings in regular expressions, including backslash, caret, pipes, and grouping symbols like parentheses, brackets, and braces, and why escaping matters.

Escape metacharacters in regular expressions by using a backslash before each metacharacter, turning them into literal characters and enabling precise matching.

Explore advanced regex metacharacters by using backslash escapes to form \d, \D, \w, \W, \s, and \S, and see how they match digits, non-digits, word and whitespace characters.

Learn how the dot character acts as a wildcard in regular expressions, matching any character except a newline, and how escaping it matches literals in file extensions.

Explore non-printing characters in regular expressions and learn to match them with backslash sequences for tab, newline, and other whitespace.

Explore character sets and character classes with square brackets to match one character from a set, such as B or C.

Explore character ranges in regex, using character classes and sets to match a to z and 0 to 9, with hyphen as literal inside or outside sets, case sensitive.

Explore negating a character set with a caret after the opening square bracket to match any character not in the set, including 0-9 ranges.

Explore how metacharacters inside a character set alter literal matches in regular expressions. Learn to escape hyphen, backslash, and closing square bracket, and control their meaning by position.

Learn shorthand character classes such as digits, whitespace, and word characters using backslash notations like d, D, s, S, w, and W to match or negate these sets.

Explore repetition with quantifiers in regular expressions, including the question mark, asterisk, and plus, to make elements optional or repeatable and to match various spellings, dates, or formats.

Master limiting repetition in regular expressions using curly brace quantifiers {n}, {n,}, and {n,m}, with examples for exactly three digits via \d{3}, using boundaries \b for full matches.

Learn greedy and lazy regular expressions, where greedy quantifiers match as much as possible and lazy ones favor the shortest strings, with backtracking to resolve matches.

Explore the lazy behavior of regular expressions, learn how lazy quantifiers replace greedy matches using ? and negated character classes, and discover how this reduces backtracking and improves efficiency.

Explore anchors in regular expressions, using the caret for the start of a line, the dollar sign for the end, and multiline mode to match boundaries within text.

Explore word boundaries with regex, using \b and \B to anchor matches between \w and \W characters, and apply them to match whole words and four-letter sequences.

Explore groups in regular expressions, using opening and closing parentheses to capture and quantify subpatterns, apply alternation, and reference grouped matches with backreferences like \1 and \2.

Master alternation in regular expressions by using the vertical bar to choose between patterns, forming groups and character classes, and matching domain names like dot com or dot net.

Explore nested alternation in regular expressions, using parenthesized groups to match Toyota or Honda and optional extensions like cc configurations, demonstrating how the engine selects one option at a time.

Explore how capturing and non-capturing groups work in regex, assign group numbers left to right, reference them with \1, and use (?:) to avoid capturing.

Explore lookaround assertions in regular expressions, using lookahead and lookbehind to match elements only when specific words follow or precede. Learn positive and negative variants and their purpose.

Learn positive lookahead in regular expressions to match patterns only when followed by a word or currency marker, with examples like bill followed by paid and amounts followed by USD.

Master negative lookahead in regular expressions to match patterns not followed by a specified word, illustrated by bill not followed by a period and three-digit numbers not followed by USD.

Master positive lookbehind assertions in regular expressions, learning the syntax (?<=...) and how to match words like course when preceded by free, or worker when preceded by social.

Learn the negative lookbehind assertion to match 'book' only when a preceding word does not appear, using the (?<!...) syntax, and explore lookaround's atomic behavior.

Master how regex matches numbers using simple patterns, word boundaries, and the digit class, then use the plus quantifier and braces to match one to four digit numbers.

Learn to create regex patterns that match number ranges from 0 to 9, 1 to 9, 0 to 10, and 1 to 10 using square brackets, grouping, and alternation.

Learn to build regex ranges for 1 to 12 and 0 to 16 using square brackets, grouping, alternation, adapt to 0 to 12, 1 to 16, or 0 to 15.

Construct a regex to match 1 to 31 by three parts—1–9, 10–29, and 30–31—using character classes and ranges. Apply this pattern to validate day ranges in calendars.

Learn to match number ranges in regex, building 0-9 and 10-99 patterns. Discover three-part matching for 0-100 with word boundaries.

Learn to build regex patterns that match the 0–127 numeric range by splitting into 0–9, 10–99, 100–119, and 120–127, then combine with or operator.

Learn to build regex patterns that match numbers from 0 to 999 and extend to 0 to 1000 by combining three parts: 0–9, 10–99, and 100–999, with the or operator.

Learn to build a radix for numbers 1 to 9999 by combining four parts—1–9, 10–99, 100–999, and 1000–9999—and assemble a regex that matches 1 to 9999.

Analyze date formats and craft a complete regular expression by dividing data into columns, applying quantifiers, character classes, and escaping to match days.

Learn to craft regular expressions for postal codes, from five-digit zip formats to five-digit hyphen four-digit codes, using anchors, word boundaries, and optional groups for United Kingdom patterns.

Learn to craft a robust regex for IP addresses by breaking 0-255 into three parts, using alternation and capturing groups to validate and match valid addresses.