JavaScript How to filter array of objects by dynamic key?

Question

I have an array which contains objects with dynamic keys, my aim is to find if this array contains or not specific key, How can this be achieved?

 let arr = [ {item1: { key: 'sdfd', value:'sdfd' }}, {item2: { key: 'sdfd', value:'sdfd' }}, {item3: { key: 'sdfd', value:'sdfd' }} ] let target = 'item1' //result array let arr = [ {item1: { key: 'sdfd', value:'sdfd' }}, ]

Answer 1

Use Array#filter() and the in operator

 let arr = [ {item1: { key: 'sdfd', value:'sdfd' }}, {item2: { key: 'sdfd', value:'sdfd' }}, {item3: { key: 'sdfd', value:'sdfd' }} ] let target = 'item1' console.log( arr.filter(i => target in i) )

Answer 2

Based on your title, I assume you want to try using array.filter , so follow up your attempt of using array.filter , this is an opion:

 let arr = [ {item1: { key: 'sdfd', value:'sdfd' }}, {item2: { key: 'sdfd', value:'sdfd' }}, {item3: { key: 'sdfd', value:'sdfd' }} ] let target = 'item1' let newarr= arr.filter(each=>Object.keys(each).toString() ==target) console.log(newarr)

Answer 3

JavaScript has built-in functions that return the object's keys for you:

var x = {
    name : "Romulo",
    age : 17
}

console.log(Object.keys(x))

Output:

["name","age"]

This returns an array, you just need check if your key is in it.

Answer 4

You can use Array.filter method and Object.hasOwn method for this, please never use the in operator it has some precedence issues.

 const arr = [ {item1: { key: 'sdfd', value:'sdfd' }}, {item2: { key: 'sdfd', value:'sdfd' }}, {item3: { key: 'sdfd', value:'sdfd' }} ] function filterByKey(list, target) { return list.filter( item => Object.hasOwn(item, target) ); } const target = "item1"; console.log( filterByKey(arr, target) );

Answer 5

Already Data

[
  {item1: { key: 'sdfd', value:'sdfd' }},
  {item2: { key: 'sdfd', value:'sdfd' }},
  {item3: { key: 'sdfd', value:'sdfd' }}
]

Want Data

Want the data from target , when target is item1 :

[
  {item1: { key: 'sdfd', value:'sdfd' }}
]

Current Code

 let arr = [ {item1: { key: 'sdfd', value:'sdfd' }}, {item2: { key: 'sdfd', value:'sdfd' }}, {item3: { key: 'sdfd', value:'sdfd' }} ] let target = 'item1' // result array let want = [ {item1: { key: 'sdfd', value:'sdfd' }}, ]

The Answer

 let arr = [ {item1: { key: 'sdfd', value:'sdfd' }}, {item2: { key: 'sdfd', value:'sdfd' }}, {item3: { key: 'sdfd', value:'sdfd' }} ] let target = 'item1' // result array let want = [ {item1: { key: 'sdfd', value:'sdfd' }}, ] let answer = arr.filter(object => object[target]) console.log('answer:', answer)

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