给定一个单词数组和一个字符串，我如何计算给定字符串中的所有单词

function countWords(wordArray, inputString) {
  let count = 0;
  for (let i = 0; i < wordArray.length; i++) {
    if (inputString.indexOf(wordArray[i]) !== -1) {
      count++;
    }
  }
  return count;
}

// 示例用法
const words = ["apple", "banana", "orange"];
const input = "I have an apple and a banana";
const wordCount = countWords(words, input);
console.log("单词数量:", wordCount);