Enumerable Ruby Methods

gistfile1.txt

#For processing iterations

Array#each
Calls block once for each element in self, passing that element as a parameter.

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#Return array / object after iterations

Enumerable#map / Enumerable#collect
Returns a new array with the results of running block once for every element in enum.
If no block is given, an enumerator is returned instead.

Object#tap
Yields x to the block, and then returns x. The primary purpose of this method is to “tap into” a method chain, in order to perform operations on intermediate results within the chain.

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#Opposites

Enumerable#reject
Returns an array for all elements of enum for which block is false (see alsoEnumerable#find_all).

Enumerable#select
Returns an array containing all elements of enum for which block is not false (see alsoEnumerable#reject).

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#Equivalent, different order for pipes

Enumerable#each_with_object
Iterates the given block for each element with an arbitrary object given, and returns the initially given object.
[1, 2, 3, 4].each_with_object([]) { |element, result| result << element }

Enumerable#inject
Combines all elements of enum by applying a binary operation, specified by a block or a symbol that names a method or operator.
[1, 2, 3, 4].inject([]) { |result, element| result << element }