Question 191210 in Javascript Question posted in
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Javascript – How to extract specific from an object

How can I remove an property from an array? I wish to remove the property that includes:

someObject = { number: '1', month: 'march', year: '2023' }

And I have an array:

someArray = ['month', 'year'] or a string 'month, year'

And want to extract so that I get:

finalObject = {  month: 'march', year: '2023' }
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3

Answers


  1. 0

    To remove an object from an array based on specific properties, you can use the filter() method along with the includes() method. Here’s how you can achieve the desired result:

    const someObject = { number: '1', month: 'march', year: '2023' };
const someArray = ['month', 'year']; // or const someArray = 'month, year';

// Convert the someArray string to an array if needed
const propertiesToRemove = Array.isArray(someArray) ? someArray : someArray.split(', ');

// Filter the properties of someObject based on propertiesToRemove
const finalObject = Object.keys(someObject)
  .filter(key => propertiesToRemove.includes(key))
  .reduce((obj, key) => {
    obj[key] = someObject[key];
    return obj;
  }, {});

console.log(finalObject);

    In this code, we first define the someObject and someArray variables as provided. Then, we convert the someArray string to an array if it is in string format.

    Next, we use Object.keys() to get an array of keys from someObject. We filter this array based on whether the properties in propertiesToRemove are present using the includes() method. Then, using reduce(), we create a new object finalObject by iterating over the filtered keys and assigning the corresponding values from someObject to the finalObject.

    Finally, we log the finalObject to the console, which will contain only the properties specified in someArray or someArray string.

    Note: The code assumes that the properties to remove exist in someObject. If there’s a possibility that some properties might not exist in someObject, you can add additional checks to handle such cases.

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  2. 0

    loop over keys and values with Object.entries with the help of filter to let only keys that exist in propertiesToExtract and turn them back into object with Object.fromEntries

    const someObject = { number: '1', month: 'march', year: '2023' } 
const propertiesToExtract = ['month', 'year']; //if it is string 'month, year' turn it into array with the help of .split(', ');
const finalObject = Object.fromEntries(Object.entries(someObject).filter(([key,value])=>propertiesToExtract.includes(key)));
console.log(finalObject); // {  month: 'march', year: '2023' }
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  3. 0

    We can write a function that maps your keys into [key, value] subarrays, using the initial object to extract the values, then use Object.fromEntries to combine these into a new object:

    const extract = (object, keys) =>
  Object.fromEntries(keys.map(key => [key, object[key]]))

const someObject = { number: '1', month: 'march', year: '2023' } 
const someArray = ['month', 'year']

console.log(extract(someObject, someArray))

    Update

    A comment asked to include only those keys whose values actually appear in the original object. This is only a minor tweak:

    const extract = (object, keys) =>
  Object.fromEntries(keys.flatMap(key => key in object ? [[key, object[key]]] : []
))
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