ruby find frequency in array self.all

To find the frequency of elements in an array self.all in Ruby, you can use the group_by method in combination with transform_values and count. Here's an example code snippet:

frequency = self.all.group_by(&:itself).transform_values(&:count)

Let's break down the steps:

1. group_by(&:itself): This method groups the elements in the array based on their values. The &:itself is a shorthand notation for the identity function, which means it returns the element itself. This step creates a hash where the keys are unique elements from the array, and the values are arrays containing all occurrences of each element.

2. transform_values(&:count): This method applies the count method to each value in the hash. The &:count is another shorthand notation that calls the count method on each array of values. This step transforms the values in the hash from arrays to the count of occurrences for each element.

The resulting frequency hash will have unique elements from the array as keys and the count of occurrences as values.