OverSimplified: Variables

Sina Nikmaram — Sun, 28 Nov 2021 21:36:47 +0000

Welcome! In this series, I try to oversimplify CS concepts in an attempt to help us all better understand them. Thanks for your time, enjoy!

What are variables?

Variables are names we assign to storage slots in our computers memory.
In the picture above, imagine each container is a slot of memory in our computer.
- The food itself is data sitting in a slot of memory.
- The labels are variable names we give to that slot of memory.

How do we use variables?

We use variables to retrieve data sitting in named storage slots

num1 = 1900   // Save 1900 in storage and name the slot num1
num2 = 121    // Save 121 in storage and name the slot num2
sum(num1 + num2)   // Add data in storage slots num1 & num2

What are the benefits of using variables?

Use simple names to evaluate complex expressions
Rename any storage slot that's holding data
Replace the data in any storage slot
Use a single name for similar values in a list of data

Descriptive Variable Naming (... and why it's important!)

In my second attempt to oversimplify using a food analogy:
- Sugar and Salt look the same but they taste completely different
- It is important that we put them in properly labeled containers or we might get weird tasting food.
- It is also important that we put data in properly named storage slots or we will get weird expression results / errors.
Inaccurate variable names will confuse other developers and your future self, which could lead to unexpected results & bugs

As mundane as variables seem, using them properly is crucial to being a good developer.

BONUS: Variable Typing

Some programming languages require us to explicitly define what data type the variables storage slot will hold.

int num1 = 1900   // Variable that only stores integers
str str1 = "A string"   // Variable that only stores strings

Typing helps productivity by showing us errors when we use a variable incorrectly (Ex: Adding a boolean variable and an integer variable).

OverSimplified: Programming Languages

Sina Nikmaram — Sun, 28 Nov 2021 06:20:44 +0000

Welcome! In this series, I try to oversimplify CS concepts in an attempt to help us all better understand them. Thanks for your time, enjoy!

What is a Programming Language?

Programming Languages are tools that provide us with a set of rules and keywords which we can use to communicate with computers.

Okay so... how does this help us communicate?

Computers only understand Binary (1's and 0's) or Machine Code.
Programming Languages allow us to write code that is legible to us, but can also be compiled into machine code.

(If you want to take a deep dive into how computers read and execute code I recommend watching this video.)

Low-Level vs High-Level Languages

Lower Level Languages (Assembly, Machine Code, etc...):
- Require management of hardware processes
- Harder to read/write
- Quicker to compile/execute
Higher Level Languages (Python, JS, etc...):
- Hide hardware processes from us / abstract them away
- Easier to read/write
- Slower to compile/execute
Abstraction is a buzzword that refers to the level of control a language requires us to have over hardware processes.

Statically Typed vs Dynamically Typed Languages

Types refer to how a language treats variables.
Statically typed languages:
- Define the data types of variables
- Variables can not have a value with a different data type

int numTen = 10
str greeting = "Hello World"

Dynamically typed languages:
- Data type of variable = data type of the value
- Allow us to assign and reassign any value to any variable

numTen = 10
numTen = "Hello World"

Best Programming Languages to get you employed in 2023

Entry level:
- JavaScript (Web Development)
- Python (Data Science & A.I.)
- Swift (Mobile)
Robotics and Gaming:
- C++
Blockchain:
1. Solidity
2. Rust
3. Go
Enterprise:
- Python
- C++
- Java

DEV Community: Sina Nikmaram