Definition and Usage. That way you could easily render them grouped by their starting time. A JavaScript object is a collection of unordered properties. If you use objects as maps from strings to values, you should only work with own properties and ignore enumerability. use Array.prototype.reduce() method to construct the desired array −, JavaScript group a JSON object by two properties and count, Sort Array of objects by two properties in JavaScript. When the group is open, the group row is removed and in its place the child rows are displayed. However, I added groupByProperties as a non-enumerable property of Array.prototype so it doesn't appear in for..in enumerations. How to group an array of objects by key (12) Does anyone know of a (lodash if possible too) way to group an array of objects by an object key then create a new array of objects based on the grouping? Code Review Stack Exchange is a question and answer site for peer programmer code reviews. This contains very little — a