Find if two arrays are repeated in array and then select them

Question

I have multiple arrays in a main/parent array like this:

var array = [[1, 17], [1, 17], [1, 17], [2, 12], [5, 9], [2, 12], [6, 2], [2, 12]];

<

Answer 1

For a different take, you can first sort your list, then loop through once and pull out the elements that meet your requirement. This will probably be faster than stringifying keys from the array even with the sort:

var arr = [[1, 17], [1, 17], [1, 17], [2, 12], [5, 9], [2, 12], [6, 2], [2, 12]]
arr.sort((a, b) => a[0] - b[0] || a[1] - b[1])

// define equal for array
const equal = (arr1, arr2) => arr1.every((n, j) => n === arr2[j])

let GROUP_SIZE = 3
first = 0, last = 1, res = []

while(last < arr.length){
    if (equal(arr[first], arr[last])) last++
    else {
        if (last - first >= GROUP_SIZE)  res.push(arr[first])
        first = last
    }
}
if (last - first >= GROUP_SIZE)  res.push(arr[first])
console.log(res)