IntelliSense & Code Completion
IntelliSense is VS Code's intelligent code-completion engine. It provides auto-complete suggestions, parameter info, quick info pop-ups, and member lists — all powered by language servers.
1How IntelliSense Works
IntelliSense is powered by a Language Server Protocol (LSP) server running in the background. The server analyses your code and sends completions, diagnostics, and hover information to VS Code in real time. This is why TypeScript/JavaScript and Python have richer IntelliSense than less popular languages.
2Triggering Completions
Ctrl+Space Trigger suggestion list Ctrl+Shift+Space Trigger parameter hints F12 Go to definition Alt+F12 Peek definition (inline) Shift+F12 Find all references Ctrl+K Ctrl+I Show hover info
3TypeScript / JavaScript IntelliSense
TS/JS get the richest IntelliSense because VS Code bundles TypeScript natively. Even plain .js files benefit from type inference. Add a jsconfig.json at the root to enable project-wide awareness:
{ "compilerOptions": { "target": "ES2022", "checkJs": true }, "include": ["src/**/*"] }
4IntelliSense for Python
Install the Python extension and select your interpreter (Ctrl+Shift+P → Python: Select Interpreter). Pylance then gives you import completions, type stubs, inlay hints and from x import y auto-imports.
5Quick Fixes & Code Actions
When VS Code detects an error, a lightbulb (💡) appears in the gutter. Click it or press Ctrl+. to see available quick fixes: auto-imports, rename refactors, extract method, fix spelling and more.