Question

Hello I need coming up with a valid regular expression It could be any identifier name that starts with a letter or underscore but may contain any number of letters, underscores, and/or digits (all letters may be upper or lower case).
For example, your regular expression should match the following text strings: “_”, “x2”, and “This_is_valid” It should not match these text strings: “2days”, or “invalid_variable%”.

So far this is what I have came up with but I don’t think it is right

/^[_\w][^\W]+/

Answer 1

The following will work:

/^[_a-zA-Z]\w*$/

Starts with (^) a letter (upper or lowercase) or underscore ([_a-zA-Z]), followed by any amount of letter, digit, or underscore (\w) to the end ($)

Read more about Regular Expressions in Perl