javascript - 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]];

here are the array's for simpler reading:

[1, 17]
[1, 17]
[1, 17]
[2, 12]
[5, 9]
[2, 12]
[6, 2]
[2, 12]
[2, 12]

I want to select the arrays that are repeated 3 or more times (> 3) and assign it to a variable. So in this example, var repeatedArrays would be [1, 17] and [2, 12].

So this should be the final result:

console.log(repeatedArrays);
>>> [[1, 17], [2, 12]]

I found something similar here but it uses underscore.js and lodash.

How could I it with javascript or even jquery (if need be)?

Answer 1

Try this

array.filter(( r={}, a=>!(2-(r[a]=++r[a]|0)) ))

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

var r= array.filter(( r={}, a=>!(2-(r[a]=++r[a]|0)) ))

console.log(JSON.stringify(r));