MODULE 1 OF 8 • THEORY
1. Basic Type Annotations
basicTypeScript enforces static type parameters (string, number, boolean, arrays). Annotating variables catches typo mismatches at compilation before executing commands in browsers.
syntax.ts
const timeoutMs: number = 10000;
const pageTitle: string = "Dashboard";When to Use
Use type annotations for complex configs, helper inputs, or global state parameters to guarantee correct variables are supplied.
Best Practice
Always avoid the "any" type because it disables TypeScript checks. Prefer "unknown" if a server response is dynamic, and narrow it down later.
Compiler Diagnostics
tsc v5.0.4[tsc] Ready to type check ts-types.ts...
[Node.js] Click "Run Code" to compile and run.