Function groupBy

Groups the elements of an array based on the given function

Example

groupBy([6.1, 4.2, 6.3], Math.floor); // {4: [4.2], 6: [6.1, 6.3]}

Example

groupBy(['one', 'two', 'three'], 'length'); // {3: ['one', 'two'], 5: ['three']}