JavaScript Functions

Write reusable logic.

JavaScript

const average = values => values.reduce((a, b) => a + b, 0) / values.length;
console.log(average([82, 91, 76, 95]));

Output

Explanation

Functions accept arguments and return results. An arrow function is a concise way to express a small function.

Explore the dry run

Guided walkthroughReady

1const average = values => values.reduce((a, b) => a + b, 0) / values.length;

2console.log(average([82, 91, 76, 95]));

Start to inspect the source, values, and output. These prepared steps explain the published sample; grouped loop steps describe multiple iterations.

View the complete dry-run table

Prepared trace of the published program. Some rows group repeated iterations.
Step / line	What happens	State after step	Output so far
	Create the average function; its body has not run yet.	`—`	—
	Pass four values into average. reduce sums them to 344, then divide by 4.	`return = 86`	86