Nested Destructuring in JavaScript or Node.js

JavaScript introduced the destructuring assignment back in 2015. The destructuring assignment is a way to unpack properties of an object or items from arrays into variables using a syntax that looks like objects or arrays.

This tutorial shows you how to use nested destructuring in JavaScript.

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  3. Generate a Random ID or String in Node.js or JavaScript
  4. Remove Extra Spaces From a String in JavaScript or Node.js
  5. Remove Numbers From a String in JavaScript or Node.js
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  8. How to Check if a Value is a String in JavaScript or Node.js
  9. Check If a String Includes All Strings in JavaScript/Node.js/TypeScript
  10. Check if a Value is a String in JavaScript and Node.js
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  12. Split a String into a List of Characters in JavaScript and Node.js
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  16. Split a String into a List of Words in JavaScript or Node.js
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  18. Check If a String Is in Lowercase in JavaScript or Node.js
  19. Check If a String is in Uppercase in JavaScript or Node.js
  20. Get the Part After First Occurrence in a String in JavaScript or Node.js
  21. Get the Part Before First Occurrence in a String in JavaScript or Node.js
  22. Get the Part Before Last Occurrence in a String in JavaScript or Node.js
  23. Get the Part After Last Occurrence in a String in JavaScript or Node.js
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  26. Append Characters or Words to a String in JavaScript or Node.js (Coming soon)
  27. Check if a String is Empty in JavaScript or Node.js (Coming soon)
  28. Ensure a String Ends with a Given Character in JavaScript or Node.js (Coming soon)
  29. Left-Trim Characters Off a String in JavaScript or Node.js (Coming soon)
  30. Right-Trim Characters Off a String in JavaScript or Node.js (Coming soon)
  31. Lowercase the First Character of a String in JavaScript or Node.js (Coming soon)
  32. Uppercase the First Character of a String in JavaScript or Node.js (Coming soon)
  33. Prepend Characters or Words to a String in JavaScript or Node.js (Coming soon)

Using Nested Destructuring in JavaScript

The concept of destructuring assignments applies recursively in JavaScript. You can destructure properties from an object or array from the root level and also from nested levels.

Here’s an example using nested destructuring to retrieve properties from an exemplary user object:

const user = {  
  nested: { 
    a: 'foo',
    b: [
      'first item',
      'second item',
      'third item',
    ]
  }
}

const {  
  nested: {
    a,
    b: [first, , third]
  }
} = user

console.log({ a, first, third })  
// {
//   a: 'foo',
//   first: 'first item',
//   third: 'third item'
// }

Destructuring nested properties follows the way of assigning key-value-pairs in an object. The difference is that you’re using this way on the left side of the equal sign:

const { nested: { something } } = sourceObject  

Please notice in the example that you can also destructure nested arrays and skip values. The example retrieves the first and third item from the b array.

That’s it!


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