Ruby Array Filter Map

In ruby 2 7 this filter map method does this in one pass.

Ruby array filter map.

Ruby 2 7 has added enumerable filter map as a shorthand for filter map in a single call. With rubyconf 2019 behind us and ruby 2 7 releasing this december it s the perfect time to go through what are the new features in the newest 2 x ruby version and also the last release before 3 0. I had to chose to do either of the following. The enumerable mixin provides collection classes with several traversal and searching methods and with the ability to sort.

To be clear do not write something which has been explained already. Adding enumerable filter map 78 1 conversation 0 commits 1 checks 0 files changed 4. Filter map do foo bar baz foo next unless bar bar. There are convenient enumerable flat map and enumerable filter map methods but the problem is that they cannot be used at the same time.

But the missing operation was intersection which has another hard to remember short version. I can not say much about array compact but from the name filter map alone i would assume that first a filter is used as a positive select and then the map is applied. By declan meehan get the most out of ruby by using the select map and reduce methods together image from kgntechnologiesyou should absolutely never ever repeat yourself when writing code. This comes in pretty handy for creating mapped arrays in a simpler way.

In other words do not repeat yourself twice. I had a use case to do map on an enumerable with 1 level flattening while skipping nil values. Ruby 2 6 introduced array union difference methods to match the more succinct equivalents of array and array. This is called tautology and when writing code it should be avoided at all times.

As you see filter map creates a new array after first filtering desired results and then maps to get expected array. Alfonsojimenez wants to merge 1 commit into ruby.