RegEx 01

What is a lexer generator?

• A tool for generating patterns

• A tool for generating compilers

• A tool for generating tokens

• A tool for generating scanners

What is a token in the context of lexical analysis?

• A string of characters

• A categorized block of text

• A pattern for matching strings

• A type of regular expression

What does a lexeme represent?

• A rule describing string matches

• An instance of a string that matches a pattern

• A type of lexical analyzer

• A category of tokens

Which of the following describes a pattern?

• A categorized block of text

• A rule describing which strings match a given token

• An instance of a string

• A type of regular expression

What does the regular expression [a-zA-Z_] match?

• Any special character

• Any digit

• Any alphabetical character or underscore

• Any whitespace character

What does the metacharacter * signify in regular expressions?

• Zero or more occurrences

• No occurrences

• One or more occurrences

• Exactly one occurrence

What does the expression (ab)+ match?

• Any number of 'ab'

• Only 'ab'

• At least one 'ab'

• None of the above

Which of the following is NOT a type of token in programming languages?

• Identifiers

• Operators

• Reserved words

• Comments

What does the regular expression [^abc] match?

• Any uppercase letter

• Any digit

• Only 'a', 'b', or 'c'

• Any character except 'a', 'b', or 'c'

What is the purpose of the vertical bar | in regular expressions?

• To group expressions

• To separate alternatives

• To indicate a range

• To match any character