Regular expressions with Regex class in Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the <code>Regex</code> class in Kotlin?

The <code>Regex</code> class in Kotlin is used to work with regular expressions, allowing you to search, match, and manipulate text based on patterns.

beginner

How do you create a Regex object to match the word "cat" in Kotlin?

You create it by calling Regex("cat"). This creates a pattern that looks for the exact sequence "cat" in text.

beginner

What does the matches() function of a Regex object do?

The matches() function checks if the entire input string exactly matches the pattern defined by the Regex.

intermediate

How can you find all occurrences of a pattern in a string using Regex?

Use the findAll() function on a Regex object. It returns a sequence of all matches found in the input string.

intermediate

What is the difference between containsMatchIn() and matches() in Regex?

containsMatchIn() checks if the pattern appears anywhere inside the string, while matches() requires the whole string to match the pattern exactly.

Which Kotlin class is used to work with regular expressions?

A Regex

B Pattern

C Matcher

D String

The Regex class in Kotlin is designed for regular expression operations.

What does Regex("abc").matches("abc") return?

A true

B false

C Throws an error

D null

The matches() function returns true if the entire string matches the pattern exactly.

Which function finds all matches of a pattern in a string?

A containsMatchIn()

B replace()

C matches()

D findAll()

findAll() returns all occurrences of the pattern in the input string.

What does containsMatchIn() check?

A If the pattern is empty

B If the pattern appears anywhere in the string

C If the string is empty

D If the entire string matches the pattern

containsMatchIn() returns true if the pattern is found anywhere inside the string.

How do you create a Regex to match any digit in Kotlin?

A Regex("[a-z]")

B Regex("d")

C Regex("\\d")

D Regex("\\w")

The pattern \\d matches any digit character.

Explain how to use the Kotlin Regex class to check if a string contains a specific pattern.

Think about how to create a pattern and check if it appears anywhere in the text.

Describe the difference between the matches() and findAll() functions in the Regex class.

One checks the entire string, the other finds many matches inside.