JSFiddle - React, Tailwind, and code Playground

by Richard Hunter

HTML

<div id="app">

</div>

JavaScript

const foo = [3, 5, 1, 8];
const bar = [8, 4, 3, 2, 5];
const moo = [2, 4, 7, 8, 5];
function blah(...arrays) {
	const result = [];
  for (let i = 0; i < arrays.length; i++) {
  	for(let j = 0; j < arrays[i].length; j++) {
    	const item = arrays[i][j];
      // for other arrays, do array.includes(item)
      const isCommonItem = arrays.reduce((memo, arr, index) => {

      	if (index !== i) {

      		return memo && arr.includes(item)
        }
        return memo;
      }, true);
      
      if(isCommonItem) {
      	result.push(item);
      }
    }
  }
  return result;
}


const result = blah(foo, bar, moo);

console.log(result);