JavaScript Fundamentals · Functions · Lesson 14 of 48

Arrow Functions

Concept

Arrow Functions

Arrow functions are a shorter syntax for writing functions, especially handy for short, one-line logic.

When the function body is a single expression, you can even drop the curly braces and the return keyword — the expression's value is returned automatically.

By the end of this lesson

Explain the core idea behind Arrow Functions.
Predict output before running a change.
Test one realistic and one unusual input.
Use the result to make the next decision.

How to study this page

1. Read one concept.
2. Change the example.
3. Run, compare, and explain.
4. Complete the challenge below.

Syntax

const name = (param1, param2) => expression;

ExampleRunnable

const multiply = (a, b) => a * b;
console.log(multiply(6, 7));

Try it Yourself »

Arrow function with a full body

const describe = (n) => {
  const kind = n % 2 === 0 ? "even" : "odd";
  return n + " is " + kind;
};
console.log(describe(4));

Note: Once you add curly braces, you need an explicit return statement again, just like a regular function.

Self-check before continuing

Without looking at the example, describe what changes when you modify one input in Arrow Functions. Then reopen the editor and prove your explanation with a small test.

You are ready to continue when you can predict, test, and explain the result.

Your turn

Rewrite the greet function from the first lesson as an arrow function.

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Console

Output will appear here...