javascript get duplicates of multiple arrays code example

Example 1: javascript get same elments from multiple arrays

var result = arrays.shift().filter(function(v) {
    return arrays.every(function(a) {
        return a.indexOf(v) !== -1;
    });
});

Example 2: javascript create array with repeated values

Array(5).fill(2)
//=> [2, 2, 2, 2, 2]