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reduceWhich

TS JS Deno

Returns the minimum/maximum value of an array, after applying the provided function to set comparing rule.

Use Array.prototype.reduce() in combination with the comparator function to get the appropriate element in the array. You can omit the second parameter, comparator, to use the default one that returns the minimum element in the array.

typescript
const reduceWhich = <T extends number | string | AnyObject = number>(
arr: T[],
comparator: Function = (a: number, b: number) => (a - b) as number
) => arr.reduce((a: T, b: T) => (comparator(a, b) >= 0 ? b : a));
typescript
reduceWhich([1, 3, 2]); // 1
reduceWhich([1, 3, 2], (a, b) => b - a); // 3
reduceWhich(
[
{ name: "Tom", age: 12 },
{ name: "Jack", age: 18 },
{ name: "Lucy", age: 9 },
],
(a, b) => a.age - b.age
); // {name: "Lucy", age: 9}