A certain programming classroom Ruby basic application function

Application function of review display system

When I was reviewing the curriculum of a certain programming class, it was recommended to implement applied functions, so I tried it. Caution -It is just an implementation example! There are many more efficient implementations and alternative answers. ・ Because it is a fairly basic curriculum, the meaning of application is different from your imagination. It's just an extension that has no answer in the curriculum.

Answer example immediately

1. Define menu display as a separate function

Paste the review display part (the part displayed by puts) that was used in advance into the new function. Don't forget to prepare formal arguments at this time and to pass the actual arguments in show ("hash name") at the caller.

review.rb

def show(review)
  line = "------------------------------------"
  puts"Genre:#{review[:genle]}\n#{line}"
  puts"title:#{review[:title]}\n#{line}"
  puts"Impressions:\n#{review[:text]}\n#{line}"
  puts"Scoring:#{review[:point]}\n#{line}"
end

2. Add new review items

All you have to do is add a new input item (puts) in the function that posts the review, wait for input with gets, and assign the input value to the hash. By the way, since it is necessary to add new puts for review display, it is more efficient to do the "processing to make display a separate function" work of *** 1 *** first.

review.rb

def write(hairetu)
  post = {}
  puts "Please enter a genre:"
~~~abridgement~~~
  puts "Please rate with a maximum of 100 points:"
  point = gets.to_i
  while point > 100
    puts"0~Please enter a number of 100"
    point = gets.to_i
  end
  post[:point] = point
~~~abridgement~~~

*** (Because the entered value is converted to a numerical value with .to_i, do not add ".chomp", be careful not to uselessly add \ n and start a new line when displaying) *** (This time, I added a scoring item, which is annoying, so I wrote it like this, but if it is a normal character string, I can write it in the same way as other items.)

3. "Read review" cannot be selected when no review is written

By writing "&& box.length> 0", you can prevent the read function (function for reading reviews) from being called unless the contents of the array containing the reviews (hash) are 0 or more.

review.rb

while true
  puts "Number of reviews:#{box.length}"
  puts"[0]I write a review"
  puts"[1]Read reviews"
  puts"[2]Quit the app"
  if choice==0
~~~abridgement~~~
  elsif choice==1 && box.length > 0
    read(box)
~~~abridgement~~~
end

4. If the number of reviews you want to see is larger than the number of reviews, re-enter it.

review.rb

  puts "Please enter the number of the review you want to see:"
  choice = gets.to_i
  while choice > box.length 
    puts "Please enter the number of an existing review:"
    choice = gets.to_i
  end

By writing in this way, you can set up a while method that keeps re-entering the value if the number entered by the user is larger than the number of elements in the array box. *** By the way *** In this description, the reviews posted recently when the user enters 0 or a string will be displayed. There are various solutions, but the simplest one is

review.rb

  if choice == 0
    puts "Invalid value"
    return 
  else
~~~Processing after the while statement~~~
end

It is a method to enclose the process with the conditional statement of if. When I tried it, both 0 and the character string are repelled firmly. Please note that if you put puts after return, the read function will end silently. Also, please note that if you do not write the esle part firmly, it will end silently as well.

Sample code

review.rb

box = []
def write(hairetu)
  post = {}
  puts "Please enter a genre:"
  post[:genle] = gets.chomp
  puts "Please enter a title:"
  post[:title] = gets.chomp
  puts "Please enter your impression:"
  post[:text] = gets.chomp
  puts "Please rate with a maximum of 100 points:"
  point = gets.to_i
  while point > 100
    puts"0~Please enter a number of 100"
    point = gets.to_i
  end
  post[:point] = point
  show(post)
  hairetu << post
  return hairetu
end

def read(box)

  box.each_with_index do |reviews,index|
    index += 1
    puts "#{[index]}:#{reviews[:title]}Review of"
  end
  puts "Please enter the number of the review you want to see:"
  choice = gets.to_i
  if choice == 0
    puts "Invalid value"
    return 
  else
  while choice > box.length 
    puts "Please enter the number of an existing review:"
    choice = gets.to_i
  end
  choice -= 1
  review = box[choice]
  show(review)
end
end

def show(review)
  line = "------------------------------------"
  puts"Genre:#{review[:genle]}\n#{line}"
  puts"title:#{review[:title]}\n#{line}"
  puts"Impressions:\n#{review[:text]}\n#{line}"
  puts"Scoring:#{review[:point]}\n#{line}"
end

def exit
  exit
end

def error
  puts "Invalid value"
end

while true
  puts "Number of reviews:#{box.length}"
  puts"[0]I write a review"
  puts"[1]Read reviews"
  puts"[2]Quit the app"
  choice = gets.to_i
  if choice==0
    box = write(box)
  elsif choice==1 && box.length > 0
    read(box)
  elsif choice==2
    exit
  else
    error
  end
end

To be honest, there are still many possibilities for errors, so if you find any flaws, please comment.