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dioltas | 12 years ago

Just tried to understand the last bit myself.

So he's doing 0["constructor"] which gives the constructor of a number, Number. Then he's 0["constructor"]["constructor"] gives the constructor of Number, which is like a function, so he gets Function.

    var y = (0)["constructor"]["constructor"];
    y == Function;                                 // true
Then he basically does this ($.$ == Function):

    Function(
        Function(
            "return \"alert('I love you');\""
        )()
    )();
The inner function just returns the string "alert('I love you');", which then becomes the body for the outer function.

I don't know why they didn't make it:

Function ("alert('I love you');")();

Maybe they needed more chars for the heart. That was a good little crash course in javascript Function constructors!

discuss

order

adam-a|12 years ago

I was a bit confused by the double Function call too. The string input to the first Function is:

    "return"ale\162t(\"\111\40lo\166e\40\171ou.\"\40)""
which when evaluated becomes:

    "alert("I love you." )"
He gets the other letters from names of types and other JS native things. I guess he couldn't get 'r', 'I', ' ', 'v' or 'y' and so had to make them using the octal escape codes.