Tuesday, November 5, 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, 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 code 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 items 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 the array object, the hash object has an each method that can be used to apply a block of code on each item in the hash. First, create a simple hash object that contains some contact information: contact_info { name Bob, phone 111-111-1111 } Then, call the each 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 the each method for an array object with one crucial difference. For a hash, you create two elements- one for the hash key and one for the value. Like the array, these elements are placeholders that are used to pass each key/value pair into the code block as Ruby loops through the hash. You can easily extend the code block to multiple lines by using do 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 the block is defined as everything after the elements (in pipes) and before the end statement.
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