PHP
A server-side scripting language that powers a huge share of the web.
1. Introduction to PHP
A server-side language that runs before the page reaches the browser — and why that matters for what PHP can and can't do.
2. Variables
PHP variables always start with a dollar sign, and don't need a declared type.
3. Echo & String Concatenation
Joining strings together with the dot operator — PHP's own way of building combined output.
4. Operators
Arithmetic, comparison, and logical operators — including the stricter three-equals comparison.
5. Conditionals
Branching with if, elseif, and else — familiar C-family syntax with curly braces.
6. Loops
Repeating code with for, while, and foreach — PHP's dedicated tool for stepping through arrays.
7. Functions
Defining reusable logic with the function keyword.
8. Arrays
Indexed and associative arrays, and how foreach steps through either kind.