反转数组

解法一

function reverseArry(arry) {
  const str = arry.join(" ");
  const result = [];
  let word = "";
  for (let i = 0, len = str.length; i < len; i++) {
    if (str[i] != " ") {
      word += str[i];
    } else {
      result.unshift(word);
      word = "";
    }
  }

  result.unshift(word);
  return result;
}

console.log(reverseArry(["I", "am", "a", "student"]));
// ["student", "a", "am", "I"]

解法二

function reverseArry(arry) {
  const result = [];
  const distance = arry.length - 1;
  for (let i = distance; i >= 0; i--) {
    result[distance - i] = arry[i];
  }

  return result;
}