nkhil · April 10, 2020 12:46
diff --git a/explanation.js b/explanation.js
 const property = obj[key];
 // obj[key] here will be '1991'.

 acc[property] = acc[property] || [];
 // At this point acc['1991'] doesn't yet exist, so it will be an empty array. This step is important as it checks if acc['1991'] exists, and if not, creates it and assigns a value of an empty array.

 acc[property].push(obj);
 // Here, all we're doing is pushing our object into the right group
	const property = obj[key];
	// obj[key] here will be '1991'.

	acc[property] = acc[property] \|\| [];
	// At this point acc['1991'] doesn't yet exist, so it will be an empty array. This step is important as it checks if acc['1991'] exists, and if not, creates it and assigns a value of an empty array.

	acc[property].push(obj);
	// Here, all we're doing is pushing our object into the right group