How can I get specific object key in map iteration

Question

I have one json file and I iterate it with map but I have a deep object key with name 'content' and I want to get specific key from it when I return my json array with map

JSON:

{ "item": [ { "title": "...", "link": "...", "content": { "_url": "How can I get this :D", ... } } ] }

My javascript code:

getAllNews = async () => { const result = await this.getResource('item/') return result.map(this._transformPosts) // Here I iterate my json } _transformPosts = (item) => { return { title: item.title, link: item.link, image: item.content._url, // and here I try get _url id: item.guide, } }

image: (item.content && item.content._url) ? item.content._url : '' should be enough. — briosheje
– briosheje, Commented May 30, 2019 at 8:03

briosheje · Accepted Answer · 2019-05-30 08:13:02Z

To correctly handle all cases, remember to always check whether the property effectively exists:

return { title: item.title, link: item.link, image: (item.content && item.content._url) ? item.content._url : '', // <-- fix here. id: item.guide, }

Possible issues probably were:

Typo on your line: item.conten._url, (should be content)
item with missing content. In that case, item.content._url would raise an exception. Adding a ternary operator like I did above will ensure the property exists, otherwise it will set the default value to ''. Feel free to change it if that's not the intended default value.

Efrain Sanjay Adhikary · Accepted Answer · 2019-05-30 08:03:22Z

first of all you have to get item key and It an array. Lets iterate over it and get the key you want to fetch

let jsonData = { "item": [ { "title": "title", "link": "link", "content": { "_url": "How can I get this :D" } } ] } function getKeyFromObject(obj,key){ return obj.item.map(each=>each.content[key]) } const url = getKeyFromObject(jsonData,"_url"); console.log(url);

VR Ferrer · Accepted Answer · 2019-05-30 08:07:20Z

Try

return { title: item.title, link: item.link, image: item['content']['_url'], id: item.guide, }

Collectives™ on Stack Overflow

How can I get specific object key in map iteration

3 Answers 3

Comments

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Related