30秒学会 JavaScript 片段 – initializeArrayWithRangeRight

Initializes an array containing the numbers in the specified range (in reverse) where start and end are inclusive with their common difference step.

Use Array.from(Math.ceil((end+1-start)/step)) to create an array of the desired length(the amounts of elements is equal to (end-start)/step or (end+1-start)/step for inclusive end), Array.prototype.map() to fill with the desired values in a range.
You can omit start to use a default value of 0.
You can omit step to use a default value of 1.

代码片段

const initializeArrayWithRangeRight = (end, start = 0, step = 1) =>
  Array.from({ length: Math.ceil((end + 1 - start) / step) }).map(
    (v, i, arr) => (arr.length - i - 1) * step + start
  );

使用样例

initializeArrayWithRangeRight(5); // [5,4,3,2,1,0]
initializeArrayWithRangeRight(7, 3); // [7,6,5,4,3]
initializeArrayWithRangeRight(9, 0, 2); // [8,6,4,2,0]