Javascript Objects as Arguments

You may want to write functions that take many arguments, some of
which are optional.
function drawElement( color, border, width, height,
left, top, zIndex) {
// Make and display an element with these variables
}
drawElement("red", 4, null, null, 100, 10);
Function signatures like this aren’t ideal for a couple of reasons:
■ It’s hard to remember the exact order of arguments.
■ You have to specify null values when you want to use the default
value for arguments in the middle of the signature.
■ Did you notice that I forgot to specify a value for zIndex? It’s hard to
count all those arguments correctly!
Passing multiple values in a single object is often a better solution:
function drawElement(options) {
// Make and display an element with the values in options
}
drawElement({
color: "red",
border: 4,
left: 100,
top: 10
});
Specifying default values is a little bit trickier with this technique. You’ll
need to create an object holding all the defaults and merge it with the
options object.