JavaScript_Succinctly

Notes
The arguments.length property was deprecated in JavaScript 1.4, but the number of
arguments sent to a function can be accessed from the length property of the function
object. Moving forward, you can get the length value by leveraging the callee property
to first gain reference to the function being invoked (i.e. arguments.callee.length).
Redefining function parameters
A function’s parameters can be redefined inside the function either directly, or by using
the arguments array. Take a look at this code:
Sample: sample87.html
var foo = false;
var bar = false;
var myFunction = function (foo, bar) {
arguments[0] = true;
bar = true;
console.log(arguments[0], bar); // Logs true true.
}
myFunction();
Notice that I can redefine the value of the bar parameter using the arguments index or
by directly reassigning a new value to the parameter.
Return a function before it is done (i.e. cancel function execution)
Functions can be cancelled at any time during invocation by using the return keyword
with or without a value. In the following sample, we are canceling the add function if the
parameters are undefined or not a number.
Sample: sample88.html
var add = function (x, y) {
// If the parameters are not numbers, return error.
if (typeof x !== 'number' || typeof y !== 'number') { return 'pass in
numbers'; }
return x + y;
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