javascript - 控制台一次仅打印一个字母，而不是完整的单词

Question

我的目标是让控制台打印从 res_GREETINGS 数组中随机选择的单词。

当我调用 randomResponse 函数时，它应该从 res_GREETINGS 数组中选择一个随机单词。相反，控制台仅随机打印一个字母。

现在，当我用 randomResponse 参数替换实际 res_GREETINGS 数组的名称时，它工作正常。当我将 "res"+ wordBank 传递给 randomResponse 时，它​​似乎只是打印出字母。

let _GREETINGS = ["hello", "hi", "hey", "nice to meet you"]
let res_GREETINGS = ["yayyy", "double yayy", "triple yay"]
let userInput = "hi"

function init(wordBank) {
  for (let i = 0; i < wordBank.length; i++) {
    if (userInput.indexOf(wordBank[i]) != -1) {
      randomResponse("res" + wordBank);
    }
  }
}

function randomResponse(arr) {
  let randomIndex = Math.floor(Math.random() * arr.length);
  console.log(arr[randomIndex]);
}

init(_GREETINGS);

Answer 1

使用 randomResponse("res"+wordBank);，您将 res 与 wordBank 连接起来 - wordBank 数组隐式转换为字符串，这意味着 randomResponse 获取的参数(arr 变量)是一个字符串，不是数组。 (因此，arr[randomIndex] 然后引用一个字母，而不是短语。)省略“res”，它会按预期工作:

let _GREETINGS = [
  "hello", "hi", "hey", "nice to meet you"
]
let res_GREETINGS = [
  "yayyy", "double yayy", "triple yay"
]
let userInput = "hi"

function init(wordBank) {
  for (let i = 0; i < wordBank.length; i++) {
    if (userInput.indexOf(wordBank[i]) != -1) {
      randomResponse(wordBank);
    }
  }
}

function randomResponse(arr) {
  let randomIndex = Math.floor(Math.random() * arr.length);
  console.log(arr[randomIndex]);
}

init(_GREETINGS);

为了使代码更具语义性和可读性，您可以考虑使用 .some 来检查输入是否存在于任何 _GREETINGS 元素中 - 它会比 for 循环更优雅一点:

let _GREETINGS = [
  "hello", "hi", "hey", "nice to meet you"
]
let res_GREETINGS = [
  "yayyy", "double yayy", "triple yay"
]
let userInput = "hi"

function init(wordBank) {
  if (wordBank.some(phrase => userInput.includes(phrase))) {
    randomResponse(wordBank);
  }
}

function randomResponse(arr) {
  let randomIndex = Math.floor(Math.random() * arr.length);
  console.log(arr[randomIndex]);
}

init(_GREETINGS);