Exercise - Regular Expressions

🔹 Beginner – Literal Matches

Exercise 1

• Task: Match all occurrences of the word cat.

• Sample text:

  The cat sat on the catalog next to another cat.

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Exercise 2

• Task: Match the email domain example.com.

• Sample text:

  Contact me at john@example.com or jane@sample.org.

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🔹 Intermediate – Metacharacters & Character Classes

Exercise 3

• Task: Match any digit.

• Sample text:

  Order numbers: 123, 456, A789.

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Exercise 4

• Task: Match any word ending with .jpg or .png.

• Sample text:

  photo.jpg, logo.png, notes.txt

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Exercise 5

• Task: Match any word that starts with a capital letter.

• Sample text:

  Alice went to Wonderland with Bob and charlie.

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🔹 Quantifiers

Exercise 6

• Task: Match all sequences of 2 to 4 digits.

• Sample text:

  Codes: 12, 345, 6789, 12345.

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Exercise 7

• Task: Match repeated laughter like ha, haha, hahaha, etc.

• Sample text:

  He said "ha", then "haha", and finally "hahahaha".

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🔹 Groups & Capturing

Exercise 8

• Task: Match names in "Last, First" format and swap them to "First Last" using search & replace.

• Sample text:

  Smith, John Doe, Jane

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Exercise 9

• Task: Extract all HTML tags (just the tag name).

• Sample text:

  <div>Hello</div><span>World</span>

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🔹 Advanced – Lookaheads

Exercise 10

• Task: Match any number that is followed by kg.

• Sample text:

  50kg 100g 25kg 300ml

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Exercise 11

• Task: Match any word that is not followed by a comma.

• Sample text:

  Apple, Orange Banana, Grape

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Exercise 12

• Task: Match passwords that contain at least one digit (validation example).

• Sample text:

  abc123 password hello42