JavaScript Syntax

Definition: Syntax is the set of rules for writing the language. A JavaScript program is a list of statements the browser runs one at a time, top to bottom.

Example 1 — statements and semicolons

Each statement usually ends with a semicolon ;. They are mostly optional, but adding them is a safe habit:

let x = 5;
let y = 6;
let z = x + y;
console.log(z);

Example 2 — case sensitivity

myName and myname are two different things:

let myName = "Sam";
let myname = "Alex";
console.log(myName, myname);

Example 3 — spaces and line breaks are ignored

Extra spacing does not change behaviour, so use it to stay readable:

let price = 5;
let quantity = 3;
let total = price * quantity;
console.log(total);

💡 Convention: JavaScript names use camelCase — first word lowercase, capitalise each next word: firstName, totalPrice.