Converting function arguments that weren't formally declared to accept into an Array.

gistfile1.js

// Create a reference to the Array.slice "static" method.
var slice = [].slice;

// call some function with one required argument.
var somefunction = function (requiredArgument) {
    
    // arguments is an Array-like local variable available within all functions.
    // arguments refers to the function's arguments within the function, you can use the 
    // arguments object if you call a function with more arguments than it is formally declared to accept.
    // https://developer.mozilla.org/en/JavaScript/Reference/Functions_and_function_scope/arguments

    // slice method can also be called to convert Array-like objects / collections to a new Array. 
    // You just bind the method to the object. The arguments inside a function is an example of 
    // 'array-like object'. Binding can be done with the .call function of Function.prototype
    // and it can also be reduced using [].slice.call(arguments) instead of Array.prototype.slice.call.
    // https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/slice#Array-like_objects
    var args = slice.call(arguments, 1);

    console.log (args); // ["1", "2", "3"]
}

somefunction("i am required", "1", "2", "3");