Destructuring for get the first property of an object?

-1

For arrays, we can define the properties depending on it's indexes like:

const arr = [1, 2, 3];

const [first, second, third] = arr;

console.log(first, second, third)

I'm just wondering if there's a possible solution to do it's reverse with objects like:

const obj = {first: "a", second: "b", third: "c"}

    const {0, 1, 2} = obj; 

//expected: "a", "b", "c"

edited Nov 16 '18 at 11:32

asked Nov 16 '18 at 11:20

Gergő Horváth

566115

4

Objects don't have a "first", they aren't ordered. Also 0, 1 and 2 aren't valid identifiers. Neither of your snippets works, and it's not clear what you'd expect as an outcome.

– jonrsharpe
Nov 16 '18 at 11:22

1

Keys in object don't have an order You can use Map or Array only

– HMR
Nov 16 '18 at 11:23

@jonrsharpe try the first snippet. It will work. What I expect as an outcome is quite clear in the comment as I think. Secondly, the "like" word shows that it should work like in the example.

– Gergő Horváth
Nov 16 '18 at 11:27

2

No it doesn't, I get a SyntaxError (e.g. missing variable name or unexpected string, depending on the implementation). And it might be clear to you, but if you're asking here it also needs to be clear to other people.

– jonrsharpe
Nov 16 '18 at 11:29

1

please add the wanted result as well.

– Nina Scholz
Nov 16 '18 at 11:29

|
show 3 more comments

-1

For arrays, we can define the properties depending on it's indexes like:

const arr = [1, 2, 3];

const [first, second, third] = arr;

console.log(first, second, third)

I'm just wondering if there's a possible solution to do it's reverse with objects like:

const obj = {first: "a", second: "b", third: "c"}

    const {0, 1, 2} = obj; 

//expected: "a", "b", "c"

edited Nov 16 '18 at 11:32

asked Nov 16 '18 at 11:20

Gergő Horváth

566115

4

Objects don't have a "first", they aren't ordered. Also 0, 1 and 2 aren't valid identifiers. Neither of your snippets works, and it's not clear what you'd expect as an outcome.

– jonrsharpe
Nov 16 '18 at 11:22

1

Keys in object don't have an order You can use Map or Array only

– HMR
Nov 16 '18 at 11:23

@jonrsharpe try the first snippet. It will work. What I expect as an outcome is quite clear in the comment as I think. Secondly, the "like" word shows that it should work like in the example.

– Gergő Horváth
Nov 16 '18 at 11:27

2

No it doesn't, I get a SyntaxError (e.g. missing variable name or unexpected string, depending on the implementation). And it might be clear to you, but if you're asking here it also needs to be clear to other people.

– jonrsharpe
Nov 16 '18 at 11:29

1

please add the wanted result as well.

– Nina Scholz
Nov 16 '18 at 11:29

|
show 3 more comments

-1

For arrays, we can define the properties depending on it's indexes like:

const arr = [1, 2, 3];

const [first, second, third] = arr;

console.log(first, second, third)

I'm just wondering if there's a possible solution to do it's reverse with objects like:

const obj = {first: "a", second: "b", third: "c"}

    const {0, 1, 2} = obj; 

//expected: "a", "b", "c"

edited Nov 16 '18 at 11:32

asked Nov 16 '18 at 11:20

Gergő Horváth

566115

For arrays, we can define the properties depending on it's indexes like:

const arr = [1, 2, 3];

const [first, second, third] = arr;

console.log(first, second, third)

I'm just wondering if there's a possible solution to do it's reverse with objects like:

const obj = {first: "a", second: "b", third: "c"}

    const {0, 1, 2} = obj; 

//expected: "a", "b", "c"

const arr = [1, 2, 3];

const [first, second, third] = arr;

console.log(first, second, third)

const arr = [1, 2, 3];

const [first, second, third] = arr;

console.log(first, second, third)

const obj = {first: "a", second: "b", third: "c"}

    const {0, 1, 2} = obj; 

//expected: "a", "b", "c"

const obj = {first: "a", second: "b", third: "c"}

    const {0, 1, 2} = obj; 

//expected: "a", "b", "c"

javascript

edited Nov 16 '18 at 11:32

asked Nov 16 '18 at 11:20

Gergő Horváth

566115

edited Nov 16 '18 at 11:32

asked Nov 16 '18 at 11:20

Gergő Horváth

566115

edited Nov 16 '18 at 11:32

asked Nov 16 '18 at 11:20

Gergő Horváth

566115

asked Nov 16 '18 at 11:20

Gergő Horváth

566115

asked Nov 16 '18 at 11:20

Gergő Horváth

566115

4

Objects don't have a "first", they aren't ordered. Also 0, 1 and 2 aren't valid identifiers. Neither of your snippets works, and it's not clear what you'd expect as an outcome.

– jonrsharpe
Nov 16 '18 at 11:22

1

Keys in object don't have an order You can use Map or Array only

– HMR
Nov 16 '18 at 11:23

@jonrsharpe try the first snippet. It will work. What I expect as an outcome is quite clear in the comment as I think. Secondly, the "like" word shows that it should work like in the example.

– Gergő Horváth
Nov 16 '18 at 11:27

2

No it doesn't, I get a SyntaxError (e.g. missing variable name or unexpected string, depending on the implementation). And it might be clear to you, but if you're asking here it also needs to be clear to other people.

– jonrsharpe
Nov 16 '18 at 11:29

1

please add the wanted result as well.

– Nina Scholz
Nov 16 '18 at 11:29

|
show 3 more comments

4

Objects don't have a "first", they aren't ordered. Also 0, 1 and 2 aren't valid identifiers. Neither of your snippets works, and it's not clear what you'd expect as an outcome.

– jonrsharpe
Nov 16 '18 at 11:22

1

Keys in object don't have an order You can use Map or Array only

– HMR
Nov 16 '18 at 11:23

@jonrsharpe try the first snippet. It will work. What I expect as an outcome is quite clear in the comment as I think. Secondly, the "like" word shows that it should work like in the example.

– Gergő Horváth
Nov 16 '18 at 11:27

2

No it doesn't, I get a SyntaxError (e.g. missing variable name or unexpected string, depending on the implementation). And it might be clear to you, but if you're asking here it also needs to be clear to other people.

– jonrsharpe
Nov 16 '18 at 11:29

1

please add the wanted result as well.

– Nina Scholz
Nov 16 '18 at 11:29

Objects don't have a "first", they aren't ordered. Also 0, 1 and 2 aren't valid identifiers. Neither of your snippets works, and it's not clear what you'd expect as an outcome.

– jonrsharpe
Nov 16 '18 at 11:22

Keys in object don't have an order You can use Map or Array only

– HMR
Nov 16 '18 at 11:23

@jonrsharpe try the first snippet. It will work. What I expect as an outcome is quite clear in the comment as I think. Secondly, the "like" word shows that it should work like in the example.

– Gergő Horváth
Nov 16 '18 at 11:27

No it doesn't, I get a SyntaxError (e.g. missing variable name or unexpected string, depending on the implementation). And it might be clear to you, but if you're asking here it also needs to be clear to other people.

– jonrsharpe
Nov 16 '18 at 11:29

please add the wanted result as well.

– Nina Scholz
Nov 16 '18 at 11:29

|
show 3 more comments

4 Answers
4

active

oldest

votes

You could take the values and assign this to an array for destructuring.

The order is actually dtermined by the insertation order or if a key is like a valid index of an array, it is sorted numerically to top.

const

    object = { first: "a", second: "b", third: "c" },

    [first, second, third] = Object.values(object);



console.log(first, second, third);

For extracting a an arbitrary position, you vould take an object with an index an object property assignment pattern [YDKJS: ES6 & Beyond] for a new valid variable.

const

    object = { first: "a", second: "b", third: "c" },

    { 2: foo } = Object.values(object);



console.log(foo);

answered Nov 16 '18 at 11:39

Nina Scholz

195k15107179

add a comment |

You do it like this for objects:

const obj = {foo: 123, bar: 'str'}



const {foo, bar} = obj

answered Nov 16 '18 at 11:34

Nurbol Alpysbayev

4,8241533

add a comment |

It isn't.

Objects are not designed to be ordered, so there isn't a first property per se.

You could convert an object into an array of its values first …

const obj = {

  first: "a",

  second: "b",

  third: "c"

}

const array = Object.values(obj);

const [foo, bar, baz] = array;

console.log({

  foo,

  bar,

  baz

});

… but it is unlikely to be useful and it certainly wouldn't be intuitive code that is easy to maintain.

edited Nov 16 '18 at 11:38

answered Nov 16 '18 at 11:22

Quentin

657k728931056

add a comment |

Try this:

const obj = {first: "a", second: "b", third: "c"}

const indexes = [0, 1, 2]

indexes.map( (val) => { return Object.values(obj)[val] } ) //["a", "b", "c"]

answered Nov 16 '18 at 11:51

javimovi

318110

add a comment |

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4 Answers
4

active

oldest

votes

4 Answers
4

active

oldest

votes

You could take the values and assign this to an array for destructuring.

The order is actually dtermined by the insertation order or if a key is like a valid index of an array, it is sorted numerically to top.

const

    object = { first: "a", second: "b", third: "c" },

    [first, second, third] = Object.values(object);



console.log(first, second, third);

For extracting a an arbitrary position, you vould take an object with an index an object property assignment pattern [YDKJS: ES6 & Beyond] for a new valid variable.

const

    object = { first: "a", second: "b", third: "c" },

    { 2: foo } = Object.values(object);



console.log(foo);

answered Nov 16 '18 at 11:39

Nina Scholz

195k15107179

add a comment |

You could take the values and assign this to an array for destructuring.

The order is actually dtermined by the insertation order or if a key is like a valid index of an array, it is sorted numerically to top.

const

    object = { first: "a", second: "b", third: "c" },

    [first, second, third] = Object.values(object);



console.log(first, second, third);

For extracting a an arbitrary position, you vould take an object with an index an object property assignment pattern [YDKJS: ES6 & Beyond] for a new valid variable.

const

    object = { first: "a", second: "b", third: "c" },

    { 2: foo } = Object.values(object);



console.log(foo);

answered Nov 16 '18 at 11:39

Nina Scholz

195k15107179

add a comment |

You could take the values and assign this to an array for destructuring.

The order is actually dtermined by the insertation order or if a key is like a valid index of an array, it is sorted numerically to top.

const

    object = { first: "a", second: "b", third: "c" },

    [first, second, third] = Object.values(object);



console.log(first, second, third);

For extracting a an arbitrary position, you vould take an object with an index an object property assignment pattern [YDKJS: ES6 & Beyond] for a new valid variable.

const

    object = { first: "a", second: "b", third: "c" },

    { 2: foo } = Object.values(object);



console.log(foo);

answered Nov 16 '18 at 11:39

Nina Scholz

195k15107179

You could take the values and assign this to an array for destructuring.

The order is actually dtermined by the insertation order or if a key is like a valid index of an array, it is sorted numerically to top.

const

    object = { first: "a", second: "b", third: "c" },

    [first, second, third] = Object.values(object);



console.log(first, second, third);

For extracting a an arbitrary position, you vould take an object with an index an object property assignment pattern [YDKJS: ES6 & Beyond] for a new valid variable.

const

    object = { first: "a", second: "b", third: "c" },

    { 2: foo } = Object.values(object);



console.log(foo);

const

    object = { first: "a", second: "b", third: "c" },

    [first, second, third] = Object.values(object);



console.log(first, second, third);

const

    object = { first: "a", second: "b", third: "c" },

    [first, second, third] = Object.values(object);



console.log(first, second, third);

const

    object = { first: "a", second: "b", third: "c" },

    { 2: foo } = Object.values(object);



console.log(foo);

const

    object = { first: "a", second: "b", third: "c" },

    { 2: foo } = Object.values(object);



console.log(foo);

answered Nov 16 '18 at 11:39

Nina Scholz

195k15107179

answered Nov 16 '18 at 11:39

Nina Scholz

195k15107179

answered Nov 16 '18 at 11:39

Nina Scholz

195k15107179

answered Nov 16 '18 at 11:39

Nina Scholz

195k15107179

add a comment |

You do it like this for objects:

const obj = {foo: 123, bar: 'str'}



const {foo, bar} = obj

answered Nov 16 '18 at 11:34

Nurbol Alpysbayev

4,8241533

add a comment |

You do it like this for objects:

const obj = {foo: 123, bar: 'str'}



const {foo, bar} = obj

answered Nov 16 '18 at 11:34

Nurbol Alpysbayev

4,8241533

add a comment |

You do it like this for objects:

const obj = {foo: 123, bar: 'str'}



const {foo, bar} = obj

answered Nov 16 '18 at 11:34

Nurbol Alpysbayev

4,8241533

You do it like this for objects:

const obj = {foo: 123, bar: 'str'}



const {foo, bar} = obj

answered Nov 16 '18 at 11:34

Nurbol Alpysbayev

4,8241533

answered Nov 16 '18 at 11:34

Nurbol Alpysbayev

4,8241533

answered Nov 16 '18 at 11:34

Nurbol Alpysbayev

4,8241533

answered Nov 16 '18 at 11:34

Nurbol Alpysbayev

4,8241533

add a comment |

It isn't.

Objects are not designed to be ordered, so there isn't a first property per se.

You could convert an object into an array of its values first …

const obj = {

  first: "a",

  second: "b",

  third: "c"

}

const array = Object.values(obj);

const [foo, bar, baz] = array;

console.log({

  foo,

  bar,

  baz

});

… but it is unlikely to be useful and it certainly wouldn't be intuitive code that is easy to maintain.

edited Nov 16 '18 at 11:38

answered Nov 16 '18 at 11:22

Quentin

657k728931056

add a comment |

It isn't.

Objects are not designed to be ordered, so there isn't a first property per se.

You could convert an object into an array of its values first …

const obj = {

  first: "a",

  second: "b",

  third: "c"

}

const array = Object.values(obj);

const [foo, bar, baz] = array;

console.log({

  foo,

  bar,

  baz

});

… but it is unlikely to be useful and it certainly wouldn't be intuitive code that is easy to maintain.

edited Nov 16 '18 at 11:38

answered Nov 16 '18 at 11:22

Quentin

657k728931056

add a comment |

It isn't.

Objects are not designed to be ordered, so there isn't a first property per se.

You could convert an object into an array of its values first …

const obj = {

  first: "a",

  second: "b",

  third: "c"

}

const array = Object.values(obj);

const [foo, bar, baz] = array;

console.log({

  foo,

  bar,

  baz

});

… but it is unlikely to be useful and it certainly wouldn't be intuitive code that is easy to maintain.

edited Nov 16 '18 at 11:38

answered Nov 16 '18 at 11:22

Quentin

657k728931056

It isn't.

Objects are not designed to be ordered, so there isn't a first property per se.

You could convert an object into an array of its values first …

const obj = {

  first: "a",

  second: "b",

  third: "c"

}

const array = Object.values(obj);

const [foo, bar, baz] = array;

console.log({

  foo,

  bar,

  baz

});

… but it is unlikely to be useful and it certainly wouldn't be intuitive code that is easy to maintain.

const obj = {

  first: "a",

  second: "b",

  third: "c"

}

const array = Object.values(obj);

const [foo, bar, baz] = array;

console.log({

  foo,

  bar,

  baz

});

const obj = {

  first: "a",

  second: "b",

  third: "c"

}

const array = Object.values(obj);

const [foo, bar, baz] = array;

console.log({

  foo,

  bar,

  baz

});

edited Nov 16 '18 at 11:38

answered Nov 16 '18 at 11:22

Quentin

657k728931056

edited Nov 16 '18 at 11:38

answered Nov 16 '18 at 11:22

Quentin

657k728931056

answered Nov 16 '18 at 11:22

Quentin

657k728931056

answered Nov 16 '18 at 11:22

Quentin

657k728931056

add a comment |

Try this:

const obj = {first: "a", second: "b", third: "c"}

const indexes = [0, 1, 2]

indexes.map( (val) => { return Object.values(obj)[val] } ) //["a", "b", "c"]

answered Nov 16 '18 at 11:51

javimovi

318110

add a comment |

Try this:

const obj = {first: "a", second: "b", third: "c"}

const indexes = [0, 1, 2]

indexes.map( (val) => { return Object.values(obj)[val] } ) //["a", "b", "c"]

answered Nov 16 '18 at 11:51

javimovi

318110

add a comment |

Try this:

const obj = {first: "a", second: "b", third: "c"}

const indexes = [0, 1, 2]

indexes.map( (val) => { return Object.values(obj)[val] } ) //["a", "b", "c"]

answered Nov 16 '18 at 11:51

javimovi

318110

Try this:

const obj = {first: "a", second: "b", third: "c"}

const indexes = [0, 1, 2]

indexes.map( (val) => { return Object.values(obj)[val] } ) //["a", "b", "c"]

answered Nov 16 '18 at 11:51

javimovi

318110

answered Nov 16 '18 at 11:51

javimovi

318110

answered Nov 16 '18 at 11:51

javimovi

318110

answered Nov 16 '18 at 11:51

javimovi

318110

add a comment |

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