groupBy

Groups the elements of a sequence.

Simple

JavaScript

Enumerable.create("grape", "passionfruit", "banana",
                  "apple", "blueberry")
          .groupBy('x => x[0]')
          .each(function(grouping) {
                    // grouping[0].key = 'g'
                    // grouping[0][0] = 'grape'

                    // grouping[1].key = 'p'
                    // grouping[1][0] = 'passionfruit'

                    // grouping[2].key = 'b'
                    // grouping[2][0] = 'banana'
                    // grouping[2][1] = 'blueberry'

                    // grouping[3].key = 'a'
                    // grouping[3][0] = 'apple'
                });

With equality comparer

JavaScript

Enumerable.create("grape", "passionfruit", "banana",
                  "apple", "Blueberry")
          .groupBy('x => x[0]', 'x, y => x === y')
          .each(function(g) {
                    // grouping[0].key = 'g'
                    // grouping[0][0] = 'grape'

                    // grouping[1].key = 'p'
                    // grouping[1][0] = 'passionfruit'

                    // grouping[2].key = 'b'
                    // grouping[2][0] = 'banana'

                    // grouping[3].key = 'a'
                    // grouping[3][0] = 'apple'
  
                    // grouping[4].key = 'B'
                    // grouping[4][0] = 'Blueberry'
                });