Question Mark is represented by ? and can be keyed in using the keyboard using the SHIFT + ? in most computers. In this article let’s understand how we can create a regex for question mark and how regex can be matched for question mark values.
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.
Conditions to match a Question Mark value
The value $ should be present in the string.
Regex for checking if its a valid Question Mark value
Regular Expression-
/[?]/gmTest string examples for the above regex-
| Input String | Match Output |
|---|---|
| zero | does not match |
| Hello??? | matches |
| 1 | does not match |
| It costs $200? | matches |
| a===true ? 1 : 0 | matches |
Here is a detailed explanation of the above regex-
/[?]/gm
Match a single character present in the list below [?]
? matches the character ? with index 6310 (3F16 or 778) literally (case sensitive)
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
Hope this article was useful to check the validity of a question mark value using regex. In conclusion, understanding the usage of the question mark symbol ‘?’ and its representation in regular expressions (regex) is essential for effective text manipulation. Regex provides a powerful mechanism to search, validate, and manipulate text patterns, making it a vital tool in programming and text processing.
