Global & Window Objects

• window.document → Access the DOM.
• window.location → Access and modify the URL.
• window.history → Manage browsing history (back() / forward() / go(n)).
• window.navigator → Access browser information (navigator.userAgent).
• window.screen → Access screen details.
• window.innerWidth / innerHeight → Get the current window size.
• window.performance → Retrieve performance metrics.

globalThis (ES2020)

• A universal reference to the global object across environments (browser, Node.js, Web Workers).
• Equivalent to window in browsers, global in Node.js, self in Web Workers.
• Use globalThis for cross-platform/global variables or functions.

globalThis.setTimeout(() => console.log("Hello!"), 1000);
globalThis.myVar = 123; // Accessible anywhere globally

Dialogs & User Interaction

• window.alert(message) → Display an alert dialog.
• window.confirm(message) → Display a confirmation dialog.
• window.prompt(message, defaultValue?) → Display an input dialog.

alert("Hello, world!");
const isConfirmed = confirm("Are you sure?");
const userInput = prompt("Enter your name:");

Window Control & Utilities

• window.open(url, target) → Open a new window/tab (may be blocked by pop-up blockers).
  • target can be _self, _blank, _parent, _top.