Regex for Validating a 4-Digit Input

# Regex for validating a 4-digit input

To validate a 4-digit input, you can use the following regular expression:

### A possible regex
“`
^\d{4}$
“`

### Regex Breakdown
“`
^ # Matches the start of the string
\d{4} # Matches exactly four digits
$ # Matches the end of the string
“`

This regular expression ensures that the input consists of exactly four digits. Examples of strings that should match this regular expression are:
– `1234`
– `9876`
– `0000`

Note that this regular expression will not match any strings that contain more or fewer than four digits.