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In simple terms: iteration (iterate) refers to doing the same thing repeatedly, so the iterator (iterator) is used to do the same thing multiple times.
iterator iscollectionmethods supported. An object that stores a set of data members is called a collection. In Ruby, arrays (Array) and hashes (Hash) can be called collections.
The iterator returns all elements of the collection, one after another. Here we will discuss two types of iterators,each and collect.
The each iterator returns all elements of the array or hash.
collection.each do |variable| code end
forcollectionexecute for each element in code. Here, the collection can be an array or a hash.
#!/usr/bin/ruby ary = [1,2,3,4,5] ary.each do |i| puts i end
The output of the above examples is as follows:
1 2 3 4 5
each The iterator is always associated with a block. It returns each value of the array to the block, one after another. The values are stored in the variable i It is then displayed on the screen.
collect Iterators return all elements of the collection.
collection = collection.collect
collect method does not always need to be associated with a block.collect method returns the entire collection, regardless of whether it is an array or a hash.
#!/usr/bin/ruby
a = [1,2,3,4,5]
b = Array.new
b = a.collect{ |x|x }
puts bThe output of the above examples is as follows:
1 2 3 4 5
Note:collect method is not the correct way to copy between arrays. There is another called clone method, used to copy an array to another array.
When you want to perform some operation on each value to obtain a new array, you usually use the collect method. For example, the following code will generate an array whose values are the 10 times.
#!/usr/bin/ruby
a = [1,2,3,4,5]
b = a.collect{|x| 10*x}
puts bThe output of the above examples is as follows:
10 20 30 40 50