30秒学会 JavaScript 片段 – reduceWhich

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.

代码片段

const reduceWhich = (arr, comparator = (a, b) => a - b) =>
  arr.reduce((a, b) => (comparator(a, b) >= 0 ? b : a));

使用样例

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}