Regular expressions can be thought of as a combination of literals and metacharacters.

The correct answer is A. True.

Regular expressions are a sequence of characters that define a search pattern. They are used to search, edit, or manipulate text. Regular expressions can be thought of as a combination of literals and metacharacters.

Literals are characters that represent themselves. For example, the literal “a” represents the letter “a”. Metacharacters are characters that have special meaning in regular expressions. For example, the metacharacter * represents zero or more of the preceding character.

Regular expressions are often used in programming languages, text editors, and other software applications. They can be used to search for patterns in text, to replace text, and to extract text from a document.

Here are some examples of regular expressions:

• . matches any character
• * matches zero or more of the preceding character
• + matches one or more of the preceding character
• ? matches zero or one of the preceding character
• [] matches any one of the characters enclosed in the brackets
• [^] matches any character not enclosed in the brackets
• \w matches any word character (alphanumeric character or underscore)
• \s matches any whitespace character (space, tab, newline, etc.)
• \d matches any digit character

Regular expressions can be very powerful and can be used to perform complex searches and manipulations on text.