As promised in my last blog post: intro to objects.
Objects
Many languages have the concept of an “object.” It’s a way of organising code based around objects (things) with similar characteristics. As in, most dogs have four legs, most cars can drive forward, most houses have doors. Templates (often called Classes) are used to create objects. These templates come with empty fields (like a form), and sometimes with default values as well (such as four legs). So it could look something like this:
Human
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Name: ________
Gender: ________
Arms: _2_
Legs: _2_
As you can see some fields (name and gender) are left blank, and some (arms and legs) have a default value associated. Again, this is a template, these values are assigned for each object (often called “instance of the class”). Mine would look like this:
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Name: _Lucy_
Gender: _Female_
Arms: _2_
Legs: _2_
But objects hold more than just fields of information; they can also hold actions! Let’s build on our Human class.
Human
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Name: ________
Gender: ________
Arms: _2_
Legs: _2_
Laugh: say "hahaha!"
Run: move your legs quickly
So you can see the Human template now has two actions associated with it (laugh and run). Here’s the great part about objects: those actions are shared! I only have to write the method once and all humans can now laugh and run. Pretty slick, huh?
So a class is a template of fields (variables) and actions (methods). Each object fills out the template with it’s particular information. This is how you can write code like me.name - the me object has a name field that keeps track of me’s name. It’s also how you can write:
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fido.bark();
buddy.bark();
buster.bark();
princess.bark();
but only need to implement the bark action on the Dog template.
Object Oriented Programming is a way of organising your code into these objects for ease of use, readability, and understanding. It’s not the only programming paradigm, but it’s been popular over the years.
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