COMPILER DESIGN

Detailed explanation-1: -A regular expression can also be described as a sequence of pattern that defines a string. Regular expressions are used to match character combinations in strings. String searching algorithm used this pattern to find the operations on a string.

Detailed explanation-2: -A Regular Expression (or Regex) is a pattern (or filter) that describes a set of strings that matches the pattern. In other words, a regex accepts a certain set of strings and rejects the rest. A regex consists of a sequence of characters, metacharacters (such as .

Detailed explanation-3: -A regular expression is a pattern that the regular expression engine attempts to match in input text. A pattern consists of one or more character literals, operators, or constructs.

Detailed explanation-4: -A regular expression (aka regex) is a sequence of characters that define a search pattern, mainly for use in pattern matching with text strings. Typically, regex patterns consist of a combination of alphanumeric characters as well as special characters.

Detailed explanation-5: -Any set that represents the value of the Regular Expression is called a Regular Set.