Make Counter

easycodingJavaScriptClosuresFunctions~10 min

Asked at Google, Meta, Amazon

Overview

Implement makeCounter(initialValue) that returns a function. Each call returns the current value and increments by 1.

Constraints

The initial value is always an integer.
The returned function takes no arguments.

Examples

const counter = makeCounter(5);
counter(); // 5
counter(); // 6
counter(); // 7

Solution

Reveal solution

function makeCounter(initialValue) {
  let count = initialValue;
  return function() { return count++; };
}

make-counter.js

Make Counter

easycodingJavaScriptClosures

Overview

Implement makeCounter(initialValue) that returns a function. Each call returns the current value and increments by 1.

Constraints

The initial value is always an integer.
The returned function takes no arguments.

Examples

const counter = makeCounter(5);
counter(); // 5
counter(); // 6
counter(); // 7

Solution

Reveal solution

function makeCounter(initialValue) {
  let count = initialValue;
  return function() { return count++; };
}

NameTopicDifficulty

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