30秒学会 JavaScript 片段 – Insert value at array index

Mutates the original array to insert the given values after the specified index.

• Use Array.prototype.splice() with an appropriate index and a delete count of 0, spreading the given values to be inserted.

代码实现

const insertAt = (arr, i, ...v) => {
  arr.splice(i + 1, 0, ...v);
  return arr;
};

let myArray = [1, 2, 3, 4];
insertAt(myArray, 2, 5); // myArray = [1, 2, 3, 5, 4]

let otherArray = [2, 10];
insertAt(otherArray, 0, 4, 6, 8); // otherArray = [2, 4, 6, 8, 10]

翻译自：https://www.30secondsofcode.org/js/s/insert-value-at-array-index