I'm attempting to wrap my mind around the behavior of Javascript functions. Are they considered a function, an object, or possibly both at the same time?
I'm attempting to wrap my mind around the behavior of Javascript functions. Are they considered a function, an object, or possibly both at the same time?
In the world of JavaScript, functions are considered first-class objects. This means that they can be treated as regular objects while also retaining their function abilities.
One interesting aspect of this is that you can assign a variable to a function and even give it properties:
var addName=function(){};
addName.blah = 1;
If functions were not first-class objects, you would be limited to using the traditional function declaration syntax like this, but luckily, in JavaScript, you have both options available:
function addName(){}
It can be said that everything in Javascript is considered "data", even functions. To put it into perspective, imagine this:
var f = function() { alert('foo'); };
When you assign a function to a variable in Javascript, it's not much different from assigning a string, for example:
var f = new String('foo');
The main distinction comes down to how you use the data. With a function, you can add properties like f.bar = 'baz'; to your object. The way you interact with the variable changes depending on whether it's a function or some other type of data - using () makes sense if it's a function and doesn't if it's another type of data.
Within the realm of JavaScript, every function functions as an object.
These objects can be invoked to execute a specific task, thanks to their internal [[Call]] property.
I won't repeat what others have said about JavaScript functions being objects of first class, but if you want more insights on functions, check out this brief page:
By the way, if you're interested in delving into JavaScript and JQuery, here's a complimentary online book for your learning journey.
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