Find the index of the minimum item of an array

JavaScript version

const indexOfMin = (arr) => arr.reduce((prev, curr, i, a) => (curr < a[prev] ? i : prev), 0);

TypeScript version

const indexOfMin = (arr: number[]): number => arr.reduce((prev, curr, i, a) => (curr < a[prev] ? i : prev), 0);

Examples

indexOfMin([6, 4, 8, 2, 10]); // 3
indexOfMin([6, 4, 2, 2, 10]); // 2