Monday, November 25, 2019
Using the Each Method in Ruby
Using the Each Method in Ruby          Every array and hash in Ruby is an object, and every object of these types has a set of built-in methods. Programmers new to Ruby can learn about how to use the each method with an array and a hash by following the simple examples presented here.          Using the Each Method With an Array Object in Ruby      First,à  create an array object by assigning the array to stooges.           stooges  [Larry, Curly, Moe]          Next, call the each method and create a small block of code to process the results.           stooges.each { |stooge| print stooge  \n }          This codeà  produces the following output:          Larry Curly Moe          The each method takes two arguments- an element and a block. The element, contained within the pipes, is similar to a placeholder. Whatever you put inside the pipes is used in the block to represent each element of the array in turn. The block is the line of code that is executed on each of the array itemsà  and is handed the element to process.         You can easily extend the code block to multiple lines by using do to define a larger block:           stuff.each do |thing| print thing print \n end          This is the same as the first example, except that the block is defined as everything after the element (in pipes) and before the end statement.          Using the Each Method With a Hash Object      Just like theà  array object, theà  hash objectà  has anà  eachà  method that can be used to apply a block of code on each item in the hash.à  First, create a simpleà  hash objectà  that contains some contact information:           contact_info  { name  Bob, phone  111-111-1111 }          Then, call theà  eachà  method and create a single line block of code to process and print the results.           contact_info.each { |key, value| print key      value  \n }          This produces the following output:          name  Bob phone  111-111-1111          This works exactly like theà  each methodà  for anà  array objectà  with one crucial difference. For a hash, you createà  twoà  elements- one for theà  hashà  key and one for the value. Like the array, these elements are placeholders that are used to pass eachà  key/valueà  pair into the code block asà  Ruby loopsà  through the hash.         You can easily extend the code block to multiple lines by usingà  doà  to define a larger block:           contact_info.each do |key, value| print print key      value print \nend          This is the same as the first hash example, except that theà  blockà  is defined as everything after the elements (in pipes) and before theà  endà  statement.    
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