The code is invoking a method/function on an object by...

The code is invoking a method/function on an object by using bracket notation.

• The initial expression [666] creates an array with one element, the number 666.
• The next bracket notation ["\155\141\160"] accesses the "map" property of that array, which returns a new object.
• The final bracket notation ["\143\157\156\163\164\162\165\143\164\157\162"] accesses the "constructor" property of the new object, which refers to the constructor function of the object.

So at this point, we have a reference to the constructor function of the object created from the "map" property of the original array.

• The next part of the code ("\141\154\145\162\164(666)") is a string that represents some JavaScript code. Specifically, it's calling the "alert" function with the argument 666.
• Finally, the resulting expression (the function call "\141\154\145\162\164(666)") is invoked with the argument 666.

So in summary, the code creates an array with one element (666), accesses the "map" property of that array to get a new object, accesses the "constructor" property of that object to get a reference to its constructor function, and then invokes that constructor function with the argument "\141\154\145\162\164(666)", which in turn calls the "alert" function with the argument 666.