CODEWITHSUNDEEP
javascriptnode.jsreactjs
Chukwuemeka Maduekwe
Chukwuemeka Maduekwe

Reputation: 8526

how do i destructure an object only when key is present

how do I destructure an object only when key is present in the object or should I say destructuring using conditionals

const arts = { a: 23, b: 3, c: 5}
const {a, d} = arts
console.log(d) 
// result produces an error on execution

I want a code where "d" won't be destructured if it's not a key available in the object.

Upvotes: 2

Views: 3192

Answers (2)

Lucas Guardado
Lucas Guardado

Reputation: 51

You could also try to use a default value for the properties like so:

const arts = { a: 23, b: 3, c: 5}


const {a = undefined, // The default could be 0 if it works for your use case.
       d = undefined,
       } = arts

console.log(d) // logs: 'undefined'
console.log(a) // logs: 23

Upvotes: 3

jarrad_obrien
jarrad_obrien

Reputation: 446

const arts = { a: 23, b: 3, c: 5}

if(arts.hasOwnProperty('a')) {
  const {a} = arts
  console.log(a)
  // do something with a
}
else {
  console.log('a was not found in arts');
}

if(arts.hasOwnProperty('d')) {
  const {d} = arts
  console.log(d)
  // do something with d
}
else {
  console.log('d was not found in arts');
}

Using arts as defined above will output:

23
d was not found in arts

The hasOwnProperty() method returns a boolean indicating whether the object has the specified property as its own property (as opposed to inheriting it).

Upvotes: 1

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