How to check if value exist in a json array javascript

Question

I have the following Structure:

_id: 'blog',
    posts: [
      {
        _id: 'politics and economy',
        name: 'politics and economy',
        author: 'Mark',
      },
      {
        _id: 'random',
        name: 'random',
        author: 'Michael'
      }
    ]

My if Statement:

if(posts.name.includes("politics"){
//Doing Stuff
}

How Can I get this running? I do not know the length of the Array.

You can use the array filter method https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter to get the items from the array that match your criteria. — szczocik, Oct 14 '20 at 12:45
Does this answer your question? [How do I check if an array includes a value in JavaScript?](https://stackoverflow.com/questions/237104/how-do-i-check-if-an-array-includes-a-value-in-javascript) — JK., Oct 15 '20 at 22:55

Cedric Cholley · Accepted Answer · 2020-10-14T12:53:31.467

1

No need to know the length, you can use forEach

posts.forEach(post => {
    if(post.name.includes("politics")){
        //Doing Stuff
    }
});

edited Oct 14 '20 at 12:53

answered Oct 14 '20 at 12:47

Cedric Cholley

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1

you miss a ')' in the if statement – John Sneijder Oct 14 '20 at 12:52
1

@JohnSneijder You are right (I've copied/pasted the code from the question) It has been corrected. thx – Cedric Cholley Oct 14 '20 at 12:54

score 1 · Answer 2 · edited Oct 14 '20 at 13:22

1

You can use the method some to check if one of the posts has the value

var name = "politics";
posts.some(singlePost => {
     return singlePost.name == name;
});

edited Oct 14 '20 at 13:22

Blu

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answered Oct 14 '20 at 12:48

Tomer Levitski

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4

score 0 · Answer 3 · edited Oct 14 '20 at 13:21

0

Use the array filter method. Link

edited Oct 14 '20 at 13:21

Blu

4,036
6
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answered Oct 14 '20 at 12:47

score 0 · Answer 4 · answered Oct 14 '20 at 12:48

0

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

answered Oct 14 '20 at 12:48

NinjaDev

402
2
6

score 0 · Answer 5 · answered Oct 14 '20 at 12:54

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)
}
});

You have to loop through the posts array.

How to check if value exist in a json array javascript

5 Answers5