Regular Expressions

What is the defined set of strings in the regular expression 100|101?

• {101}
• {100}
• {100, 101}
• {100, 101, 102}

What is the use of quantifiers in regular expressions?

• To define a group of characters
• To match a specific character
• To indicate the number of occurrences of a character or group
• To specify the order of characters

Which of the following is a valid regular expression using quantifiers and groups?

• ab?a
• ab(+)a
• ab|a
• (ab)+a

Which of the following is an example of a regular expression with a quantifier?

• ab+a
• ab?a
• ab(+)a
• ab|a

How is a regular expression interpreted?

• From right to left
• It depends on the metacharacters used
• In any order
• From left to right

How does the use of a group differ from the use of alternation in regular expressions?

• A group matches a specific character, while alternation indicates alternatives for matching
• A group specifies the order of characters, while alternation indicates alternatives for matching
• A group defines a specific set of characters, while alternation indicates alternatives for matching
• There is no difference, they both serve the same purpose

What is the difference between using a quantifier and a group in regular expressions?

• A quantifier matches a specific character, while a group matches a set of characters
• A quantifier specifies the number of occurrences, while a group defines a specific set of characters
• A quantifier specifies the order of characters, while a group defines a specific set of characters
• There is no difference, they both serve the same purpose

What does the metacharacter + mean in regular expressions?

• Matches zero or one of the preceding character or group of characters
• Matches zero or more of the preceding character or group of characters
• Matches everything on the left or everything on the right
• Matches one or more of the preceding character or group of characters

What is the relationship between characters and metacharacters in regular expressions?

• Characters and metacharacters must be matched in any order
• Characters and metacharacters are not used in regular expressions
• Characters must be matched exactly, while metacharacters have special meaning
• Characters and metacharacters are interchangeable

What is the use of alternation in regular expressions?

• To indicate alternatives for matching
• To specify the order of characters
• To match a specific character
• To define a group of characters