Regular Expression Basics

C

The symbol within regular expressions represents a special character or meta-character that has a specific meaning when used in regular expressions.

The correct answer is C. Match the preceding qualifier zero or one times. This symbol is known as the question mark or the zero-or-one quantifier.

In regular expressions, a quantifier is used to specify how many times the preceding character or group should be matched. The question mark is a special quantifier that means "match zero or one occurrence of the preceding character or group." For example, the regular expression "colou?r" would match both "color" and "colour" because the question mark makes the "u" optional.

Here's a brief explanation of the other options:

A. Match the preceding qualifier one or more times. This is the meaning of the plus sign (+) quantifier. For example, the regular expression "hel+o" would match "hello" and "helllo" but not "helo".

B. Match the preceding qualifier zero or more times. This is the meaning of the asterisk () quantifier. For example, the regular expression "god" would match "god", "good", "gooood", and so on.

D. Match a literal character. This would be represented by simply typing the character in the regular expression. For example, the regular expression "cat" would match the string "cat".