# Introduction

This time, we will calculate the difference between the two numbers in the array.

## example

You want to know how many daily temperatures change from the highest and lowest temperatures in the weather forecast to manage your physical condition.

Since the maximum temperature t and the minimum temperature u of a day are input separated by spaces, output how many temperatures are changing in a day.

For example, if you enter the following, it means that the maximum temperature is 7 degrees and the minimum temperature is -3 degrees.

``````7 -3
``````

Since the temperature difference is 10, output as follows.

``````10
``````

## Before correction

``````input_line = gets.split(' ').map(&:to_i)

#Make an array before and after
before_after = input_line.each_cons(2)

before_after.each do |ba|
puts (ba - ba).abs
end

#↓ Same meaning(Disassemble and fix for easy understanding)

before_after.each do |a, b|
puts (b - a).abs
end
``````

### Commentary

``````input_line = gets.split(' ').map(&:to_i)
``````

-Get the input value with the gets method -Split the elements of the array with the split method separated by commas -The map method takes out the elements one by one and converts them to integers.

``````before_after = input_line.each_cons(2)
``````

-Each_cons (2) can be obtained by shifting two consecutive elements one by one.

``````before_after.each do |a, b|
puts (b - a).abs
end
``````

-Calculate the difference by substituting the two elements into the ʻa, b` variables -Convert to absolute value with ads method

• Pointed out ʻEach_cons (2)`finds`[[1, 2], [2, 3], [3, 4], [4, 5]]`from`[1, 2, 3, 4, 5]`Method 1 so not very useful in this case With each_slice (2), you can find`10 3` via` [[7, -3], [5, 2]] `when multiple continuations such as` 7 -3 5 2`. ..

# Edited

``````a, b = gets.split.map &:to_i
puts (a - b).abs

#If you force it to write in one line
puts gets.split.map(&:to_i).inject(:-)
``````

## Commentary

``````a, b = gets.split.map &:to_i
``````

・ Since this time we are limited to two elements, we divide the variables into ʻa and b`. -Get the input value with the gets method -Split the elements of the array with the split method -The map method takes out the elements one by one and converts them to integers.

``````puts (a - b).abs
``````

Calculate the difference between ʻa and b` and convert it to an absolute value with the ads method.

# Finally

I was able to calculate with this description, but I couldn't understand the end, so I would appreciate it if you could teach me.

Thank you for your professor this time as well. It will be a great learning experience as you will be able to discover and point out various things by sending them out. We will continue to send messages!