multidimensional default array

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I've got two multidimensional arrays:

const defaultData = [
  ["ad", 0],
  ["ae", 0],
  ["af", 0]
]

const data = [
  ["az", 20],
  ["ad", 50]
]

The desired result is:

const expected = [
  ["ad", 50],
  ["ae", 0],
  ["af", 0]
]

Here az is ignored because its not valid because its not in the defaultData. ad is valid and therefore the 0 is overwritten with the value of 50.

How would I best produce this result. Thanks?

Please assume neither array is sorted. The expected result need not be sorted either.

Either vanilla JS or Lodash is fine.

Use map to iterate over the defaultData, and find to match each iterated array against data:

const defaultData = [['ad', 0],['ae', 0],['af', 0]];
const data = [['az', 20],['ad', 50]];

const expected = defaultData.map(arr => {

  // Destructure the first element from `arr`
  // and assign it to `code`
  const [ code ] = arr;

  // `find` the array in `data` where the first element
  // matches `code`
  const found = data.find(el => el[0] === code);

  // If `found` is undefined return the whole array
  // otherwise return a new array with the code and the value
  // from the found array
  return found ? [code, found[1]] : arr;
});

console.log(expected);

6.5 — Multidimensional Arrays, Initializing two-dimensional arrays. To initialize a two-dimensional array, it is easiest to use nested braces, with each set of numbers representing a row:� A multidimensional array is an array of arrays. Each element of a multidimensional array is an array itself. For example, int [] [] a = new int [3] [4]; Here, we have created a multidimensional array named a. It is a 2-dimensional array, that can hold a maximum of 12 elements, 2-dimensional Array.

Convert the data to an object (dataByKey) with _.fromPairs(). Map the defaultData, and check if the "key" (index 0) exists in dataByKey. If it is, create a new array with the value from dataByKey. If not return the original array.

const defaultData = [
  ["ad", 0],
  ["ae", 0],
  ["af", 0]
]

const data = [
  ["az", 20],
  ["ad", 50]
]

const dataByKey = _.fromPairs(data)

const result = defaultData.map(o => o[0] in dataByKey ? [o[0], dataByKey[o[0]]] : o)

console.log(result)
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>

Initialize multidimensional arrays in C, Finally, we can initialize a multidimensional array with any value using nested for-loops. *((int*)mat + i) = 0; Note that the global and static arrays are initialized with their default values when no initializer is specified. For instance, a global integer array will be zero-initialized by default. With a multidimensional array, the loops are most likely the best approach, unless the array is small enough to initialize directly in code. If you're using a jagged array, you could initialize the first sub-array, then use Array.Copy to copy these values into each other sub-array. This will still require one iteration through the first sub array, and one loop through N-1 outer arrays, but the copy operation will be faster than the loops.

You could first create one object from data and then use map method on defaultData to create new array and get value from data by key.

const defaultData = [
  ["ad", 0],
  ["ae", 0],
  ["af", 0]
]

const data = [
  ["az", 20],
  ["ad", 50]
].reduce((r, [key, value]) => {
  r[key] = (r[key] || 0) + value;
  return r;
}, {})

const expected = defaultData.map(([key, value]) => {
  return [key, key in data ? data[key] : value] 
})

console.log(expected)

Multidimensional Arrays, You can initialize the array upon declaration, as is shown in the following example. C# Copy. // Two-dimensional array. Iterating Values of a Multidimensional Array. In order to iterate through all the elements of the multidimensional array we need to use nested for loop concept as below: # at first we will create an array of c columns and r rows. c = 4 r = 3 arr = [[0] * c for i in range(r)] # loop will run for the length of the outer list for i in range(r):

Try this out, I am using map() to create a new Array and find() to find elements from the second array.

I compare the first index item of each sub array from the default array, if any of the items from second array has the same element in its first index then I return it, if none matches, nothing is returned.

If I have a matched item then I create a new array using its elements. If I don't have a matched item I create a new using the default elements of the default item.

const defaultData = [
  ["ad", 0],
  ["ae", 0],
  ["af", 0]
]

const data = [
  ["az", 20],
  ["ad", 50]
]

let newData = defaultData.map(eachDefault => {
  let found = data.find(eachData => {
    if (eachData[0] == eachDefault[0]) {
      return true
    }
  })
  if (found) {
    return [...found]
  }
  return [...eachDefault]
})

console.log(newData)

Arrays - C++ Tutorials, By default, regular arrays of local scope (for example, those declared within a function) are left Multidimensional arrays can be described as "arrays of arrays" . In C programming, you can create an array of arrays. These arrays are known as multidimensional arrays. For example, float x[3][4]; Here, x is a two-dimensional (2d) array. The array can hold 12 elements. You can think the array as a table with 3 rows and each row has 4 columns. Similarly, you can declare a three-dimensional (3d) array. For

You can use map/reduce like this:

const defaultData = [
  ["ad", 0],
  ["ae", 0],
  ["af", 0]
]

const data = [
  ["az", 20],
  ["ad", 50]
]

const result = defaultData.map(arr => data.reduce(([dKey, dVal], [key, val]) => [ dKey, dKey === key ? val : dVal ], arr));

console.log(result);

How to declare and Initialize two dimensional Array in Java with , Another popular application of multi-dimensional arrays is in matrix manipulation. For example to represent a 3x3 matrix you need a two-dimensional array of 3� Multi dimensional arrays in COBOL are supported and it is possible to have up to 7 dimensions which is its MAX limit. But more than two dimension array creates confusion.So in general two dimensional arrays and Single dimensional arrays are used mostly. Let us see how to declare and process multi dimensional arrays in COBOL.

I realize an array of arrays is possible, but there are an equal number of items in every row, and so a 2D array is really the structure I'm after. A multidimensional array creates a nice linear memory layout while a jagged array implies several extra levels of indirection. – Alain Aug 26 '11 at 14:02

Multidimensional arrays in PHP. Multi-dimensional arrays are such type of arrays which stores an another array at each index instead of single element. In other words, define multi-dimensional arrays as array of arrays. As the name suggests, every element in this array can be an array and they can also hold other sub-arrays within.

Size of multidimensional arrays. Total number of elements that can be stored in a multidimensional array can be calculated by multiplying the size of all the dimensions. The array int x [10] [20] can store total (10*20) = 200 elements. Similarly array int x [5] [10] [20] can store total (5*10*20) = 1000 elements.

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  • Answers saying "Try this out:" are not appreciated. You should explain your code.