Predict the output of the following JavaScript code

(function (flag) { let age = Boolean(NaN === NaN ? false : flag);

console.log(age.toString()[Number(flag)]); })([]);

 

 

 

 

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Quiz Explanation

We have a self-executing function with the parameter/argument is an empty array. Noted that NaN === NaN returns false, then age gets the value flag, which is an empty array. However, the boolean value is true when we call Boolean([]).

The function toString() returns the string true and the Number([]) returns 0. Then we get "t" in the console.log. The correct answer is B.

Keep in mind that Boolean([]) ==> true but Number([]) ==> 0. And sadly NaN === NaN returns false.