The double negation operator !! calculates the truth value of a value. It's actually two operators, where !!x means !(!x) , and behaves as follows ... ... <看更多>

(double bang, double negation)?. What's the best way to answer the question "true or false?" in JavaScript. JavaScript does not bother you too ... ... <看更多>

參考資料 · MDN Expressions and operators · 程式語言教學誌JS · sitepoint JavaScript Double Negation. ... <看更多>

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It is probably not possible to get XSS given this simple character restriction. However, an attacker could inject an escape character, for example: ... <看更多>