@technobuddha > library > Random > Pick

Function: randomWeightedPick()

function randomWeightedPick<T>(list: readonly T[], random: () => number): undefined | T;

Defined in: random-weighted-pick.ts:39

Selects a random item from a list, where each item has an associated weight that determines its likelihood of being picked.

If the list is empty, it returns undefined.

Type Parameters

Type Parameter	Description
T extends Weighted	The type of items in the list, extending the Weighted interface (must have a weight property).

Parameters

Parameter	Type	Default value	Description
list	readonly T[]	undefined	The array of weighted items to pick from.
random	() => number	Math.random	A function that returns a random number between 0 (inclusive) and 1 (exclusive). Defaults to Math.random.

Returns

undefined | T

The randomly selected item based on weights, or undefined if the list is empty.

Example

const items = [
  { value: 'a', weight: 1 },
  { value: 'b', weight: 3 },
  { value: 'c', weight: 6 },
];
randomWeightedPick(items, () => 0.0); // { value: 'a', weight: 1 }
randomWeightedPick(items, () => 0.2); // { value: 'b', weight: 3 }
randomWeightedPick(items, () => 0.8); // { value: 'c', weight: 6 }
randomWeightedPick([], () => 0.5); // undefined