如何在 javascript 中编写没有 for 循环的以下代码

Question

I need help with the following program in javascript

A function, written without any loop statements, that accepts an array and produces a new array equal to the initial array with ith element (1-based) repeated i times.

i was able to write the code in for loop, just need help in writing without loop

export function stretched(a) {
    const stretchedArray = [];
    for (let [index, item] of a.entries()) {
      for (let i = 0; i < index + 1; i++) {
        stretchedArray.push(item);
      }
    }
    return stretchedArray;
}

Answer 1

This can be another approach:

 function stretched(a) { const stretchedArray = []; for (let [index, item] of a.entries()) { stretchedArray.push(...(new Array(index + 1).fill(item))) } return stretchedArray; } console.log(stretched(['a','b','c']))