how to convert 2D nested array into 2D single array in javascript

Question

I need to convert a nested array into 2D in javascript, somewhat similar to the question answered for python at link

How to convert 2d nested array into 2d array single?

For example, the array

[[[[[[[[
  [16,12],[16,13],[16,14]]
 ],
 [[[[[[
   [46,42],[46,43]
 ]]]]],[
   [62,58],[62,59],[62,60]
 ]]]]]],
  [103,102]],[[118,114],[118,115],[118,116]]
]

needs to be converted to

[[16,12],[16,13],[16,14],[46,42],[46,43],[62,58],[62,59],[62,60],[103,102],[118,114],[118,115],[118,116]]

Please help, thanks in advance

This is what I tried, finally works after many trials :


function removeNestArray2D(object) {
    var result = [];
    if (Array.isArray(object)) { // check if object is valid array
        for(var i=0; i<object.length; i++) { 
            if(!Array.isArray(object[i])) { // check is each of array element is a valid array
                return object;
            }
            else {
                var tmp = removeNestArray2D(object[i]);

                if(tmp.length == 1) {
                    result = tmp[0];
                }
                else if (tmp.length == 2 && Number.isInteger(tmp[0]) && Number.isInteger(tmp[1])) {
                    result.push(tmp);
                }
                else {
                    for (var j=0; j<tmp.length; j++) {
                        result.push(tmp[j]);
                    }
                }
            }
        }
    }
    return result;
}

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hey @AKP - what have you tried so far? And could you please edit your post so that your arrays and code are "code formatted"? It'll make it a lot easier to read. — SethGoodluck, Apr 22 '20 at 16:13
@SethGoodluck I have posted my code, thanks. Formatting rules noted. — AKP, Apr 22 '20 at 19:19

Siva K V · Accepted Answer · 2020-04-23T04:43:17.457

0

Recursive approach will help here. Check each array item if there are size 2 and both are number values then push to result array otherwise continue iteration recursively.

const arr = [[[[[[[[
  [16,12],[16,13],[16,14]]
 ],
 [[[[[[
   [46,42],[46,43]
 ]]]]],[
   [62,58],[62,59],[62,60]
 ]]]]]],
  [103,102]],[[118,114],[118,115],[118,116]]
];

const get2dArray = arr => {
  const res = [];
  const pushRecursive = arr => {
    if (arr.length == 2 && arr.every(x => Number.isInteger(x))) {
      res.push(arr);
    } else {
      arr.forEach(pushRecursive);
    }
  };
  pushRecursive(arr);
  return res;
};

console.log(get2dArray(arr));

edited Apr 23 '20 at 04:43

answered Apr 22 '20 at 17:38

Siva K V

10,561
2
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29

thanks for your code, however I was trying for a function with array as its returning result as given in my code – AKP Apr 22 '20 at 19:18
@AKP, oh ok. Just update answer to wrap in function. – Siva K V Apr 23 '20 at 04:52

score 0 · Answer 2 · answered Apr 22 '20 at 21:10


function removeNestArray2D(object) {
    var result = [];
    if (Array.isArray(object)) { // check if object is valid array
        for(var i=0; i<object.length; i++) { 
            if(!Array.isArray(object[i])) { // check is each of array element is a valid array
                return object;
            }
            else {
                var tmp = removeNestArray2D(object[i]);

                if(tmp.length == 1) {
                    result = tmp[0];
                }
                else if (tmp.length == 2 && Number.isInteger(tmp[0]) && Number.isInteger(tmp[1])) {
                    result.push(tmp);
                }
                else {
                    for (var j=0; j<tmp.length; j++) {
                        result.push(tmp[j]);
                    }
                }
            }
        }
    }
    return result;
}

how to convert 2D nested array into 2D single array in javascript

2 Answers2