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How come this code returns true?
string to match: ab
pattern: /^a|b$/
but when I put parentheses like this:
pattern: /^(a|b)$/
it will then return false.
The first pattern without the parenthesis is equivalent to
/(^a)|(b$)/.The reason is, that the pipe operator (“alternation operator”) has the lowest precedence of all regex operators: http://www.regular-expressions.info/alternation.html (Third paragraph below the first heading)