打印到控制台时，句子末尾变得不确定

Question

const words = ['hello', 'thank you', 'brother', 'welcome', 'dancing', 'milk', 'bike', 'ruffles'];

const getSentence = (words, index = 0) => {

  if (words[index] === undefined) {
    return;
  }
  return words[index] + ' ' + getSentence(words, index + 1)
}

console.log(getSentence(words));

Answer 1

问题是在上次调用中，您的函数未返回任何内容，因此它未定义打印，您应该尝试返回一些类似空字符串的内容，请尝试使用此代码，但不确定是否会执行您想要的操作，请尝试一下

const words = ['hello', 'thank you', 'brother', 'welcome', 'dancing', 'milk', 'bike', 'ruffles'];

const getSentence = (words, index = 0) => {

if (words[index] === undefined) {
    return '';
}
return words[index] + ' ' + getSentence(words, index + 1)
}

console.log(getSentence(words));