How does the extend() function work in jQuery?

Question

I saw this in a plugin:

var options = $.extend(defaults, options); 

How does it work?

What does extend() do?

Answer 1

It merges the content of one object to another. If we pass two objects, second object properties are added to the first object / first parameter

Ex: $.extend(object1, object2);

Now object1 contains properties of object2

If we want to merge two objects, then we need to pass empty object in the first parameter

Ex: var newObject = $.extend({}, object1, object2);

Now newObject contains both properties of object1 and object2.