javascript - 反转数组，让新数组中的元素与原始数组元素的长度相等 - JavaScript

Question

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我已经能够将数组反转为字符串，但无法将此字符串分配给指定长度的单个元素。我试过:

function ultimateReverse (array) {

 let newArray = array.join("").split("");
 let reversedArray = newArray.reverse();
 return reversedArray.join("");

}

console.log(ultimateReverse(["I", "like", "big", "butts", "and", "I", "cannot", "lie!"]));

//!eiltonnacIdnasttubgibekilI

但我们想要的结果是:

["!", "eilt", "onn", "acIdn", "ast", "t", "ubgibe", "kilI"]

那么根据原数组，第一个元素的长度应该是1，第二个元素的长度应该是4，第三个元素的长度应该是3，以此类推...

有没有办法将字符串拆分为元素数组，每个元素指定长度？

我想通过以下方式创建原始数组中项目长度的数组:

function ultimateReverse (array) {

let elementLengths = [];

let newArray = array.join("").split("");
let reversedArray = newArray.reverse().join("");

for (let i = 0; i < array.length; i++) {
  let element = array[i];
  elementLengths.push(element.length);
}

return reversedArray + " " + elementLengths;

}

console.log(ultimateReverse(["I", "like", "big", "butts", "and", "I", "cannot", "lie!"]));

//!eiltonnacIdnasttubgibekilI 1,4,3,5,3,1,6,4

现在，如果我可以根据原始元素的长度将字符串拆分为数组中的元素...

Answer 1

首先构建完整的反转字符串，例如

!eiltonnacIdnasttubgibekilI

然后，从一个初始长度的数组(可以提前使用 .map 完成)迭代该数组，并从反向数组中切片该长度字符串，并推送到一个数组:

function ultimateReverse(array) {
  const lengths = array.map(({ length }) => length);
  let reversedStr = [...array.join("")].reverse().join('');
  const result = [];
  lengths.forEach((length) => {
    result.push(reversedStr.slice(0, length));
    reversedStr = reversedStr.slice(length);
  });
  return result;
}

console.log(ultimateReverse(["I", "like", "big", "butts", "and", "I", "cannot", "lie!"]));

您还可以将初始反转数据保留为您拼接的数组，而不是重新分配reversedStr:

function ultimateReverse(array) {
  const lengths = array.map(({ length }) => length);
  const reversedChars = [...array.join('')].reverse();
  return lengths.map(
    length => reversedChars.splice(0, length).join('')
  );
}

console.log(ultimateReverse(["I", "like", "big", "butts", "and", "I", "cannot", "lie!"]));