I want to convert 3d array to 2d array

so I have 3d array look like this

[
  [
    ["creative fee (example)"],
    [1000]
  ],
  [
    ["Item 1...", "Item 2..."],
    [600, 1000]
  ],
  [
    ["Item 3...", "Item 4..."],
    [400, 600]
  ]
]

and want to convert to 2d array like this (expected result)

[
  ["creative fee (example)", 1000],
  ["Item 1...", 600],
  ["Item 2...", 1000],
  ["Item 3...", 400],
  ["Item 4...", 600]
]

this is what I've tried but it begins too hard

var carry = [
  [
    ["creative fee (example)"],
    [1000]
  ],
  [
    ["Item 1...", "Item 2..."],
    [600, 1000]
  ],
  [
    ["Item 3...", "Item 4..."],
    [400, 600]
  ]
],
result = []
for (var z = 0; z < carry.length; z++) {
  for (var m = 0; m < carry[z].length; m++) {
    for (var t = 0; t < carry[z][m].length; t++) {
     // console.log(carry[z][m][t])
     result[z+t] = []
     result[z+t][m] = carry[z][m][t]
    }
  }
}
console.log(result)

I want to convert 3d array to 2d array

so I have 3d array look like this

[
  [
    ["creative fee (example)"],
    [1000]
  ],
  [
    ["Item 1...", "Item 2..."],
    [600, 1000]
  ],
  [
    ["Item 3...", "Item 4..."],
    [400, 600]
  ]
]

and want to convert to 2d array like this (expected result)

[
  ["creative fee (example)", 1000],
  ["Item 1...", 600],
  ["Item 2...", 1000],
  ["Item 3...", 400],
  ["Item 4...", 600]
]

this is what I've tried but it begins too hard

var carry = [
  [
    ["creative fee (example)"],
    [1000]
  ],
  [
    ["Item 1...", "Item 2..."],
    [600, 1000]
  ],
  [
    ["Item 3...", "Item 4..."],
    [400, 600]
  ]
],
result = []
for (var z = 0; z < carry.length; z++) {
  for (var m = 0; m < carry[z].length; m++) {
    for (var t = 0; t < carry[z][m].length; t++) {
     // console.log(carry[z][m][t])
     result[z+t] = []
     result[z+t][m] = carry[z][m][t]
    }
  }
}
console.log(result)

Anyways thank you in advance

• javascript
• arrays
• multidimensional-array

• not supported by all browsers, but can be useful, take a look: developer.mozilla/en-US/docs/Web/JavaScript/Reference/… – Calvin Nunes Commented Nov 11, 2020 at 12:01

4 Answers 4

You could take a Array#flatMap approach and map pairs.

let data = [[["creative fee (example)"], [1000]], [["Item 1...", "Item 2..."], [600, 1000]], [["Item 3...", "Item 4..."], [400, 600]]],
    result = data.flatMap(([l, r]) => l.map((v, i) => [v, r[i]]));

console.log(result);

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

This should work for your case, you just need to use the spreed operator(...) to spread items and push them into an array (items) and push the results into an new array (using map in this case)

var array2D = carry.map(el => {
  var items = [];
  el.forEach(e => items.push(...e))
  return items;
});

If you need to avoid Array.flatMap (it was introduced in EMCAScript 2019), the old vanilla way would be:

  carry.map(elt => [].concat(...elt))

By using flatMap:

const result = data.flatMap(([i, j]) => i.map((a, idx) => [a, j[idx]]))

const data = [
      [
        ["creative fee (example)"],
        [1000]
      ],
      [
        ["Item 1...", "Item 2..."],
        [600, 1000]
      ],
      [
        ["Item 3...", "Item 4..."],
        [400, 600]
      ]
    ];

    const result = data.flatMap(([i, j]) => i.map((a, idx) => [a, j[idx]]))

    console.log(result)