Get a random item and remove it from an array

Remove one random item from the array and return it.

JavaScriptNode.js & browsers Version 1.0.0 · MIT · .md

function takeRandomItem(values) { return values.splice(Math.floor(Math.random() * values.length), 1)[0]; }

Usage

const pool = ['ana', 'rui', 'lia'];
const picked = takeRandomItem(pool);
pool.length; // → 2
pool.includes(picked); // → false
takeRandomItem([]); // → undefined

Lines marked → were executed in Node.js 22 and in headless Chromium, and each result was compared with the value shown. Lines marked e.g. are illustrative.

Know the limits

• Mutates the array. The original returned the one-item array from splice, such as [7], not the item; [0] unwraps it.
• Removing from the middle is O(n). To draw many items, shuffle once and pop.

The function above is the code the usage lines run. It does not validate its arguments; add checks where it receives untrusted input.

Keep exploring

• Generate a random boolean — Return true or false with equal probability.
• Generate a random floating point number in given range — Scale Math.random into [min, max).
• Generate a random hex color — Return a #rrggbb color from 24 random bits.