Why the result of this regular expression in javascript is true?

Question

alert(/[a-z]+/.test("4Nyth1n&_."));

why the output is true? doesn't it supposed to match just the alphabet from a to z (lower case)?

Answer 1

test just looks for a match of a substring. In this case, the substring yth matches. If you want to match the whole string, insert ^ and $:

alert(/^[a-z]+$/.test("4Nyth1n&_."));