jquery - Finding matches amongst multiple javascript arrays and output the repeating array

Question

I just want to find matches between multiple arrays based on first value in an array and keep the matching results.

[
    [[11,1], [22,2], [33,3]],
    [[11,1], [10,1], [22,1]],
    [[11,10], [12,1], [22,1]]
]

Above is my sample array. first unique values in those arrays are 11, 22, 33, 10, 12 so out of which 11, 22 are repeated across all the three arrays.

And would like to to produce the following array that contains matches from all given arrays:

[
    [[11,1], [22,2]],
    [[11,1], [22,1]],
    [[11,10], [22,1]]
]

I just tried with javascript reduce function, but couldn't solve it and not getting the result as expected.

Answer 1

You could filter first for common values and map the result with the filtered arrays.

const
    data = [
        [[11, 1], [22, 2], [33, 3]],
        [[11, 1], [10, 1], [22, 1]],
        [[11, 10], [12, 1], [22, 1]]
    ],
    common = data.reduce((a, b) => a.filter(([v]) => b.some(([w]) => v === w))),
    result = data.map(a => a.filter(([v]) => common.some(([w]) => v === w)));

console.log(common);
console.log(result);