In regex, the question mark ? makes the preceding character, group, or class optional, allowing it to appear zero or one time. For example, colou?r matches both 'color' and 'colour'. It's a versatile tool for handling variations in text patterns.
In regular expressions (regex), an optional character is represented using the question mark ?. This means that the preceding character or group in the regex pattern is optional, meaning it can occur zero or one times. For example:
colou?rmatches both "color" and "colour"favou?ritematches both "favorite" and "favourite"
Here's a brief explanation:
?: Matches the preceding element zero or one time. It makes the preceding character or group optional.
Remember that you can apply the ? to a character, a group, or even a character class.