Step by Step solution about How to resolve the algorithm Start from a main routine step by step in the Ruby programming language

BEGIN and END blocks in Ruby

In Ruby, BEGIN and END blocks are used to execute code before and after the main program code, respectively. They are often used for tasks such as setting up global variables, loading libraries, or cleaning up resources.

BEGIN block

The BEGIN block is executed before any other code in the program. This means that it can be used to set up global variables, load libraries, or perform any other tasks that need to be done before the main program code can run.

END block

The END block is executed after all other code in the program has finished running. This means that it can be used to clean up resources, close files, or perform any other tasks that need to be done after the main program code has finished running.

Example

The following example shows how to use BEGIN and END blocks to set up a global variable and clean up a file:

BEGIN {
 $global_variable = 1
}

END {
 File.close($file)
}

# Main program code

In this example, the BEGIN block sets the global variable $global_variable to 1. The END block closes the file $file. These blocks are executed before and after the main program code, respectively.

BEGIN {
  # begin code
}

END {
  # end code
}