Extract the data from a deeply nested key within a JSON object

Question

Extract the data from a deeply nested key within a JSON object

I'm currently working on a function that takes a key (specified as a string) and retrieves its corresponding values from a given JSON object.

Here is the JSON data I am working with:

[
  {
    "some_key1": [
      {"key": "value1"},
      {"key": "value2"},
      {"key": "value3"}
    ]
  },
  {
    "some_key2": [
      {"key": "value4"},
      {"key": "value5"},
      {"key": "value6"}
    ]
  },
  {
    "default_val": [
      {"key": "value7"},
      {"key": "value8"},
      {"key": "value9"}
    ]
  }
]

The structure of this JSON may vary, but it always consists of inner objects.

Below is the implementation of a function that will retrieve the array of values based on the provided key:

interface InnerObject {
    key: string;
}

const fetchValues = (key = "default_val"): InnerObject[] => {
    /* actual code goes here */
}

Expected output example:

> fetchValues("some_key2");
[{"key": "value4"},{"key": "value5"},{"key": "value6"}]
> fetchValues();
[{"key": "value7"},{"key": "value8"},{"key": "value9"}]

Looking forward to any elegant solutions!

javascript json typescript algorithm

Answer 1

Answer №1

Similar approach like Nick's, but utilizing find to directly retrieve the object:

const data = [
  {
    "some_key1": [
      {"key": "value1"},
      {"key": "value2"},
      {"key": "value3"}
    ]
  },
  {
    "some_key2": [
      {"key": "value4"},
      {"key": "value5"},
      {"key": "value6"}
    ]
  },
  {
    "default_val": [
      {"key": "value7"},
      {"key": "value8"},
      {"key": "value9"}
    ]
  }
];

const getValues = (key = 'default_val') => data.find(o => Object.keys(o)[0] == key);

console.log(getValues('some_key2'));
console.log(getValues());

Answer 2

Similar approach like Nick's, but utilizing find to directly retrieve the object:

const data = [
  {
    "some_key1": [
      {"key": "value1"},
      {"key": "value2"},
      {"key": "value3"}
    ]
  },
  {
    "some_key2": [
      {"key": "value4"},
      {"key": "value5"},
      {"key": "value6"}
    ]
  },
  {
    "default_val": [
      {"key": "value7"},
      {"key": "value8"},
      {"key": "value9"}
    ]
  }
];

const getValues = (key = 'default_val') => data.find(o => Object.keys(o)[0] == key);

console.log(getValues('some_key2'));
console.log(getValues());

Answer 3

Answer №2

It would be beneficial to reconsider the current data structure for more efficient searching. Perhaps transforming it into a more suitable format before conducting searches could yield better results.

A potential alternative structure may look like this:

const makeSearcher = (input, obj = Object .assign (...input)) => (key) =>
  obj [key] || obj .default_val

const input = [{some_key1: [{key: "value1"}, {key: "value2"}, {key: "value3"}]}, {some_key2: [{key: "value4"}, {key: "value5"}, {key: "value6"}]}, {default_val: [{key: "value7"}, {key: "value8"}, {key: "value9"}]}]

const search = makeSearcher (input)

console .log (search ('some_key2'))
console .log (search ())

This approach assumes only one object corresponds to each key. In cases where multiple objects share the same key, considering Nick's solution might be wise.

Although the provided O (1) search function is efficient, any logical solution is not expected to surpass O (n). Therefore, performance is unlikely to pose a significant obstacle in this scenario.

Answer 4

It would be beneficial to reconsider the current data structure for more efficient searching. Perhaps transforming it into a more suitable format before conducting searches could yield better results.

A potential alternative structure may look like this:

const makeSearcher = (input, obj = Object .assign (...input)) => (key) =>
  obj [key] || obj .default_val

const input = [{some_key1: [{key: "value1"}, {key: "value2"}, {key: "value3"}]}, {some_key2: [{key: "value4"}, {key: "value5"}, {key: "value6"}]}, {default_val: [{key: "value7"}, {key: "value8"}, {key: "value9"}]}]

const search = makeSearcher (input)

console .log (search ('some_key2'))
console .log (search ())

This approach assumes only one object corresponds to each key. In cases where multiple objects share the same key, considering Nick's solution might be wise.

Although the provided O (1) search function is efficient, any logical solution is not expected to surpass O (n). Therefore, performance is unlikely to pose a significant obstacle in this scenario.

Answer 5

Answer №3

Here is a solution:

function fetchValues(key = "default_val"): InnerObject[] {
  return data.find(item => item[key])[key];
};

Answer 6

Here is a solution:

function fetchValues(key = "default_val"): InnerObject[] {
  return data.find(item => item[key])[key];
};

Answer 7

Answer №4

To filter specific values from an array of objects based on a key, you can utilize the Array.filter method and specify the desired key as a parameter:

const data = [
  {
    "some_key1": [
      {"key": "value1"},
      {"key": "value2"},
      {"key": "value3"}
    ]
  },
  {
    "some_key2": [
      {"key": "value4"},
      {"key": "value5"},
      {"key": "value6"}
    ]
  },
  {
    "default_val": [
      {"key": "value7"},
      {"key": "value8"},
      {"key": "value9"}
    ]
  }
];

const getValues = (key = 'default_val') => data.filter(o => Object.keys(o)[0] == key);

console.log(getValues('some_key2'));
console.log(getValues());

In cases where multiple values match the search key, this code will return all matches. For more efficient retrieval when expecting only one result, consider using Array.find explained in alternative solutions.

Answer 8

To filter specific values from an array of objects based on a key, you can utilize the Array.filter method and specify the desired key as a parameter:

const data = [
  {
    "some_key1": [
      {"key": "value1"},
      {"key": "value2"},
      {"key": "value3"}
    ]
  },
  {
    "some_key2": [
      {"key": "value4"},
      {"key": "value5"},
      {"key": "value6"}
    ]
  },
  {
    "default_val": [
      {"key": "value7"},
      {"key": "value8"},
      {"key": "value9"}
    ]
  }
];

const getValues = (key = 'default_val') => data.filter(o => Object.keys(o)[0] == key);

console.log(getValues('some_key2'));
console.log(getValues());

In cases where multiple values match the search key, this code will return all matches. For more efficient retrieval when expecting only one result, consider using Array.find explained in alternative solutions.

Answer 9

Answer №5

Check out this versatile approach using object-scan

One of the key benefits is its ability to easily target deeper keys and multiple keys at once.

// Sample code snippet to demonstrate object scanning with object-scan

const myData = [{ some_key1: [{ key: 'value1' }, { key: 'value2' }, { key: 'value3' }] }, { some_key2: [{ key: 'value4' }, { key: 'value5' }, { key: 'value6' }] }, { default_val: [{ key: 'value7' }, { key: 'value8' }, { key: 'value9' }] }];

const find = (data, key) => objectScan([key], { reverse: false, rtn: 'value' })(data)

console.log(find(myData, '[*].some_key2[*]'));
// => [ { key: 'value4' }, { key: 'value5' }, { key: 'value6' } ]

.as-console-wrapper {max-height: 100% !important; top: 0}

<script src="https://bundle.run/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="4c232e26292f38613f2f2d220c7d7f6274627c">[email protected]</a>"></script>

Disclaimer: The creator of object-scan has written this post.

Answer 10

Check out this versatile approach using object-scan

One of the key benefits is its ability to easily target deeper keys and multiple keys at once.

// Sample code snippet to demonstrate object scanning with object-scan

const myData = [{ some_key1: [{ key: 'value1' }, { key: 'value2' }, { key: 'value3' }] }, { some_key2: [{ key: 'value4' }, { key: 'value5' }, { key: 'value6' }] }, { default_val: [{ key: 'value7' }, { key: 'value8' }, { key: 'value9' }] }];

const find = (data, key) => objectScan([key], { reverse: false, rtn: 'value' })(data)

console.log(find(myData, '[*].some_key2[*]'));
// => [ { key: 'value4' }, { key: 'value5' }, { key: 'value6' } ]

.as-console-wrapper {max-height: 100% !important; top: 0}

<script src="https://bundle.run/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="4c232e26292f38613f2f2d220c7d7f6274627c">[email protected]</a>"></script>

Disclaimer: The creator of object-scan has written this post.

Extract the data from a deeply nested key within a JSON object

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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