Find the intersection between two JS arrays of objects, based on an object property (using 'filter' and 'map').

intersection.js

/** Find the intersection between two JS arrays of objects
 * finds based on an object property (using 'filter' and 'map')
 */

products = [ // an array of products
  {reference:'LOWP8F7H', name:'Nike Blazer', price:120, category:1},
  {reference:'3PFH3LDP', name:'Nike Kyrie', price:340, category:1},
  {reference:'FGH4P40K', NAME:'Nike Bomber', price:70, category:0}
];

resultProducts = [ // a second array of products
	{reference:'ANFHO2f3', name:'Adidas NMD', price:90, category:1},
  {reference:'LOWP8F7H', name:'Nike Blazer', price:120, category:1},
  {reference:'3PFH3LDP', name:'Nike Kyrie', price:340, category:1}
];

// finding the intersection between them
var intersection = products.filter((product, pos, arr)=>{ // loop through each product
	var resProdRefs = resultProducts.map(mapObj => mapObj.reference); // get all refs of the resultProducts
  
  if (resProdRefs.indexOf(product.reference) > -1) return true; // if the loop product ref is in resultProduct refs
  return false; // item doesn't intersect
  
});

console.log(intersection); // returns the 2 intersecting items

// The above code can even be shortened to the following...
var intersection = products.filter(product=>{
  return resultProducts.map(mapObj => mapObj.reference).indexOf(product.reference) > -1;
});
console.log(intersection); //returns same 2 intersecting items