Regex for Validating a Digit

# Regex for validating a digit

To validate a single digit using a regular expression, you can use the following regex pattern:

### A possible regex
“`
^\d$
“`

### Regex Explanation
“`
^ # Matches the start of the string
\d # Matches a single digit (0-9)
$ # Matches the end of the string
“`

This regex pattern will match a single digit from 0 to 9. It ensures that the input consists of only one digit and no other characters.

Examples of strings that should match this regular expression are:
– `0`
– `5`
– `9`

Examples of strings that should not match this regular expression are:
– `10` (more than one digit)
– `a` (not a digit)
– ` ` (empty string)

Please note that this regex pattern is specifically for validating a single digit. If you need to validate multiple digits or a range of digits, the pattern would need to be modified accordingly.