Which of the following is used for specifying character class with metacharacter?

” option2=”{}” option3=”/+” option4=”All of the mentioned” correct=”option4″]

The correct answer is D. All of the mentioned.

A character class is a set of characters that can be matched by a regular expression. The square brackets ([]) are used to specify a character class. The curly braces ({}) are used to specify a range of characters. The plus sign (+) is used to match one or more of the preceding character. The forward slash (/) is used to specify a regular expression.

Here are some examples of character classes:

• [a-z] matches any lowercase letter.
• [0-9] matches any digit.
• [a-zA-Z] matches any letter, uppercase or lowercase.
• [^a-z] matches any character that is not a lowercase letter.
• [0-9a-z] matches any digit or lowercase letter.
• {1,3} matches one or three of the preceding character.
• {1,} matches one or more of the preceding 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 character except a newline.
• \w matches any word character (a letter, a digit, or an underscore).
• \s matches any whitespace character (a space, tab, newline, or form feed).
• \d matches any digit.
• \n matches a newline character.
• \t matches a tab character.
• \r matches a carriage return character.
• \f matches a form feed character.
• \e matches an escape character.
• \a matches an alert character.
• \b matches a backspace character.
• \v matches a vertical tab character.
• \f matches a form feed character.
• \xnn matches the character with the octal value nn.
• \unnnn matches the character with the Unicode value nnnn.
• \UNNNN matches the character with the Unicode value NNNN.

Regular expressions are used in a variety of applications, such as text processing, web development, and database management.