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Regex for one character

Regex for one character

In computer science, a character is a unit of information that represents a single letter, digit, punctuation mark, or other symbol. Characters are typically stored as sequences of bits (binary digits) in a computer's memory, and they are used to represent text, numbers, and other types of data. In this article let's understand how we can create a regex for character and how regex can be matched for a given character.

Regex (short for regular expression) is a powerful tool used for searching and manipulating text. It is composed of a sequence of characters that define a search pattern. Regex can be used to find patterns in large amounts of text, validate user input, and manipulate strings. It is widely used in programming languages, text editors, and command line tools.

Structure of a character

The character should have the following criteria and structure-

  • a character is a unit of information that represents a single letter, digit, punctuation mark, or other symbol. Characters are typically stored as sequences of bits (binary digits) in a computer's memory, and they are used to represent text, numbers, and other types of data.

Regex for checking if one character is valid or not

Regular Expression for character-

/^.$/gm

Test string examples for the above regex-

Input StringMatch Output
aedoes not match
12Gdoes not match
2matches
Amatches
;matches

Here is a detailed explanation of the above regex-

/^.$/gm

^ asserts position at start of a line
. matches any character (except for line terminators)
$ asserts position at the end of a line
Global pattern flags
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
g modifier: global. All matches (don't return after first match)

Hope this article was useful to check if the string is a valid single character or not.