Practice Recursive Steps (operations On Regular Expressions) (3.8.1.2) - Non-Deterministic Finite Automata (NFA) and Regular Expressions
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Recursive Steps (Operations on Regular Expressions)

Practice - Recursive Steps (Operations on Regular Expressions)

Learning

Practice Questions

Test your understanding with targeted questions

Question 1 Easy

What does the regular expression ∅ represent?

💡 Hint: Consider what it means to have no options.

Question 2 Easy

Explain what the empty string ϵ represents.

💡 Hint: Think about a string with no characters.

4 more questions available

Interactive Quizzes

Quick quizzes to reinforce your learning

Question 1

What does the union operation in regular expressions do?

Combines languages
Sequentially joins strings
Represents one choice

💡 Hint: Think about when one or the other is valid.

Question 2

Is the expression a* an example of Kleene star?

True
False

💡 Hint: Consider how many times 'a' can occur.

1 more question available

Challenge Problems

Push your limits with advanced challenges

Challenge 1 Hard

Create a regular expression that matches any string starting with 'A' and followed by zero or more 'a's.

💡 Hint: Focus on how to represent the starting character and repetitions afterward.

Challenge 2 Hard

Given the expressions R1 = 'cat' and R2 = 'dog', what does the expression (R1 + R2)* represent?

💡 Hint: Think about what it means to repeat those groups together.

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Reference links

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