CODEWITHSUNDEEP
javascriptjsonobjectdestructuring
Eitanos30
Eitanos30

Reputation: 1429

Why getting "Destructuring expressions can only have identifier references" when trying to destruct an object?

I have the following object:

const john = {
  family: [
    { firstName: 'david', secondName: 'jana' },
    { firstName: 'eyal', secondName: 'shani ' },
  ],
};

I want to get 'david' string in one operation. So i tried the following code:

const { family:[0]{firstName}}} = john;

But i'm getting the error :

"Destructuring expressions can only have identifier references"

Can someone tell me in simple words (cause i'm new in the language) what i'm doing wrong?

Upvotes: 0

Views: 116

Answers (1)

CertainPerformance
CertainPerformance

Reputation: 370679

To extract a deeply nested value with destructuring, the syntax is nearly identical to when declaring an object with those properties. family:[0] isn't valid syntax - instead, you need to surround the contents of family in array delimiters:

const john = {
  family: [{
      firstName: 'david',
      secondName: 'jana'
    },
    {
      firstName: 'eyal',
      secondName: 'shani '
    },
  ],
};

const { family:[{firstName}]} = john;

console.log(firstName);

But I'd highly recommend against using nested destructuring like this. It's so hard to write and read and understand. Better to use plain dot notation at least for the outer accesses, eg

const john = {
  family: [{
      firstName: 'david',
      secondName: 'jana'
    },
    {
      firstName: 'eyal',
      secondName: 'shani '
    },
  ],
};

const { firstName } = john.family[0];
console.log(firstName);

Upvotes: 3

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