Finding the size of inner arrays through destructuring

Question

Finding the size of inner arrays through destructuring

I have a data array structured in the following pattern

data = [
          [0,
            [
             ['a', [{}, ..., {}]],
             ['b', [{}, ..., {}]] 
            ]
          ],
          [1,
            [
             ['a', [{}, ..., {}]],
             ['b', [{}, ..., {}]] 
            ]
          ],
          .
          .
          .
      ]

I am attempting to find the length of the innermost arrays of objects. My current approach is as follows:

foo = ([,[[,objects]]]) => console.log(objects.length);

data.foreach(foo);

Despite my expectation, instead of printing the length of each innermost array of objects, I am only getting multiple '1's printed to the console. It appears that objects is treated as an array with a single element rather than the entire array.

Is there a way to correct this issue while maintaining this specific pattern?

Additionally, is this method of accessing values known as destructuring in JavaScript?

javascript arrays

Answer 1

Answer №1

Ah yes, here we have an illustration of destructuring assignment. Your code snippet demonstrates the concept effectively, though it appears to only output 2 results as it accesses only the first nested array within each array passed to the foo() function.

To log all the nested arrays of objects, a two-stage process is required. The initial stage involves isolating the inner arrays, followed by iterating over these inner arrays to obtain and display the lengths of the object arrays.

If we deconstruct the steps involved, it becomes easier to understand:

const foo = (array) => {
  console.log("array: ", array); // [0, [["a", [{}, {}, {}]], ["b", [{}, {}, {}]]]
  
  const [, inner] = array;
 
  console.log("inner: ", inner); // [["a", [{}, {}, {}]], ["b", [{}, {}, {}]]
  
  inner.forEach((arr) => {
    console.log("arr: ", arr); // ["a", [{}, {}, {}]]
    
    const [, object_arr] = arr;
    
    console.log("object_arr: ", object_arr); // [{}, {}, {}]
    console.log("object_arr.length: ", object_arr.length); // 3
  });
};

Answer 2

Ah yes, here we have an illustration of destructuring assignment. Your code snippet demonstrates the concept effectively, though it appears to only output 2 results as it accesses only the first nested array within each array passed to the foo() function.

To log all the nested arrays of objects, a two-stage process is required. The initial stage involves isolating the inner arrays, followed by iterating over these inner arrays to obtain and display the lengths of the object arrays.

If we deconstruct the steps involved, it becomes easier to understand:

const foo = (array) => {
  console.log("array: ", array); // [0, [["a", [{}, {}, {}]], ["b", [{}, {}, {}]]]
  
  const [, inner] = array;
 
  console.log("inner: ", inner); // [["a", [{}, {}, {}]], ["b", [{}, {}, {}]]
  
  inner.forEach((arr) => {
    console.log("arr: ", arr); // ["a", [{}, {}, {}]]
    
    const [, object_arr] = arr;
    
    console.log("object_arr: ", object_arr); // [{}, {}, {}]
    console.log("object_arr.length: ", object_arr.length); // 3
  });
};

Finding the size of inner arrays through destructuring

Answer №1

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