Function Types

TypeScript lets you define function parameter types and return types explicitly.

Syntax

TYPESCRIPT

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function add(a: number, b: number): number {
    return a + b;
}

const multiply = (a: number, b: number): number => a * b;

Function Type Annotations

TYPESCRIPT

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function add(a: number, b: number): number {
    return a + b;
}

const multiply = (a: number, b: number): number => a * b;

function greet(name: string): string {
    return `Hello, ${name}!`;
}

console.log(add(5, 3));
console.log(multiply(4, 2));
console.log(greet("SukhNexus"));

Try It Yourself

Practice

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Exercise

Practice this concept.

Answer

Write the code as shown above.

Quick Quiz

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What did you learn?

Concept A

Concept B

Concept C

Concept D

This covers the basics.

Retry Quiz

Interview Questions

Explain this concept.

It is a fundamental TypeScript feature.

Next Lesson

Optional & Default Parameters