如何检查json数组javascript中是否存在值

Question

我有以下结构：

_id: 'blog',

    posts: [

      {

        _id: 'politics and economy',

        name: 'politics and economy',

        author: 'Mark',

      },

      {

        _id: 'random',

        name: 'random',

        author: 'Michael'

      }

    ]

我的 if 语句：

if(posts.name.includes("politics"){

//Doing Stuff

}

我怎样才能让它运行？我不知道数组的长度。

Answer 1

不需要知道长度，你可以使用forEachposts.forEach(post => {    if(post.name.includes("politics")){        //Doing Stuff    }});

Answer 2

您可以使用方法 some来检查其中一篇帖子是否具有该值var name = "politics";posts.some(singlePost => {     return singlePost.name == name;});

Answer 3

if(posts.filter(post => post.name.includes("politics")).length > 0){//Doing Stuffconsole.log("One of posts has a name including politics")} 

Answer 4

使用数组过滤方法。关联

Answer 5

const posts = [      {        _id: 'politics and economy',        name: 'politics and economy',        author: 'Mark'      },      {        _id: 'random',        name: 'random',        author: 'Michael'      }    ]posts.forEach(post => {if(post.name.includes("politics")){//Do Your Stuffconsole.log(post.name)}});您必须遍历 posts 数组。