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forEach

posts.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 Stuff

console.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 Stuff

console.log(post.name)

}

});

您必须遍历 posts 数组。