Python

Python Variables and the Basic Types You Will Use Constantly

How Python variables actually work, why there's no type keyword, and one division gotcha that catches everyone once.

JavaScript

var, let and const: Why JavaScript Has Three Ways to Make a Variable

const doesn't mean frozen, and var leaks out of if blocks in a way that trips up almost everyone once.

C++

Variables, Types and the C++ Compiler

C++ forces every variable to have a declared type, and that rigidity is exactly what makes the compiler so useful.

Java

Variables and Data Types in Java

The building blocks of any Java program: how to store values and the basic types.