如何访问列表中每个对象的body属性并检查特定单词是否存在

你的代码存在两处核心问题，下面逐一修正：

1. 数组定义语法错误 #

j_list数组内部不能用const post = {...}声明对象，直接写入对象字面量即可。

修正后的j_list：

const j_list = [
  {
    "postId": 1,
    "id": 1,
    "name": "id labore ex et quam laborum",
    "email": "Eliseo@gardner.biz",
    "body": "laudantium enim quasi est quidem magnam voluptate ipsam eos\ntempora quo necessitatibus\ndolor quam autem quasi\nreiciendis et nam sapiente accusantium"
  },
  {
    "postId": 1,
    "id": 2,
    "name": "quo vero reiciendis velit similique earum",
    "email": "Jayne_Kuhic@sydney.com",
    "body": "est natus enim nihil est dolore omnis voluptatem numquam\net omnis occaecati quod ullam at\nvoluptatem error expedita pariatur\nnihil sint nostrum voluptatem reiciendis et"
  },
  {
    "postId": 1,
    "id": 3,
    "name": "odio adipisci rerum aut animi",
    "email": "Nikita@garfield.biz",
    "body": "quia molestiae reprehenderit quasi aspernatur\naut expedita occaecati aliquam eveniet laudantium\nomnis quibusdam delectus saepe quia accusamus maiores nam est\ncum et ducimus et vero voluptates excepturi deleniti ratione"
  }
];

2. 循环与字符串检查逻辑错误 #

• for...in遍历数组时拿到的是索引字符串，不是数组中的post对象，因此post.body会报错，应改用for...of遍历数组元素，或forEach方法。
• includes()方法直接返回布尔值，不需要和-1比较（indexOf()才会返回索引，找不到时返回-1）。

方案一：使用for...of循环 #

for (const post of j_list) {
  if (post.body.includes("quasi")) {
    console.log("This post contains that word");
  } else {
    console.log("This post doesn't contain any search word");
  }
}

方案二：使用forEach方法 #

j_list.forEach(post => {
  if (post.body.includes("quasi")) {
    console.log("This post contains that word");
  } else {
    console.log("This post doesn't contain any search word");
  }
});

兼容旧环境的传统for循环 #

for (let i = 0; i < j_list.length; i++) {
  const post = j_list[i];
  if (post.body.includes("quasi")) {
    console.log("This post contains that word");
  } else {
    console.log("This post doesn't contain any search word");
  }
}

内容的提问来源于stack exchange，提问作者Thestrike95