Types in Depth

Types in Depth

In this lesson — part of Data Deep Dive — you'll learn types in depth in TypeScript and why it matters in real work.

Why it matters

Types tell you what operations make sense and catch whole classes of bugs early.

Key ideas

• Common types: text, numbers, booleans
• Type conversion and coercion
• When to be explicit about types
• Type errors and how to read them

In practice

Here's how it looks in idiomatic TypeScript:

const age: number = 42;
const label: string = String(age); // number -> string
const back: number = Number(label); // string -> number
const flag: boolean = age > 18;
console.log(typeof label, back, flag);

TypeScript note: TypeScript types are erased at compile time, so conversions like String() / Number() are real runtime calls, not just type assertions.

Try it yourself

Exercise: In TypeScript, convert a number to text and back, and print both.

Recap

You now understand types in depth and can apply it in TypeScript. Mark this lesson complete and continue to the next one.