Hi, welcome to TecTerminal.

Welcome.

So, what are variables?

Well, let’s go back to our cake analogy. Let’s say you’ve gotten a recipe book, you’ve looked at the instructions, and you’re ready to bake your cake.

I would assume — and I really hope I’m right — that you won’t just get all the materials and dump them on the table, right? You would probably do something like this:

• You put sugar in a sugar container and label it sugar.
• You put flour in the flour container.
• And all the other materials are separated into their own containers.

Well, that’s kind of what variables are.

Definition

Variables are simply named containers that a computer uses to store information that you give it.

The name of the variable is set by the programmer, and then the computer takes this information and stores it somewhere in its memory.

Why do we need variables?

1. To store information.
2. To retrieve information later after it has been stored.

For example:

• Someone comes to your site and registers. They put in their email, name, and password.
• In a production system, this would be stored in a database, but in your code you store this information in variables like name, email, and age.
• When the person comes back, you can retrieve this information and say:
  “Hey, welcome John with your email john@mail.com, age 18.”

3. To change information over time.

• For example, John celebrates his birthday. He’s no longer 18 — he’s now 19.
• To update this, we retrieve the age variable (which was 18) and add 1 to it, making it 19.

These are some of the uses of variables. And believe me — in every program you write, without exception, you will be using variables a lot.

In our next lesson, we’re going to talk about data types — what they mean and how they are used in programming. See you there!