Basic Syntax and Structure

JavaScript is case-sensitive. Expressions produce values; statements control execution. Braces group blocks and lexical scope. Semicolons are sometimes inserted automatically, but consistent explicit formatting avoids surprising boundaries.

A small module

"use strict";

function square(value) {
  return value * value;
}

const input = 7;
console.log(square(input));

Use //, /* */, and documentation conventions deliberately. Modules are strict automatically and isolate top-level bindings. Identifiers support Unicode but readable project conventions matter more. Prefer small files with explicit imports/exports and format automatically. Read the first syntax or runtime error first, because later failures often cascade from it.