[RUBY] Output of how to use the slice method

As the title suggests, it outputs about the slice method.

What is the slice method?

The specified element can be extracted from the array or character string.

Various ways to use

Part 1 (Specify one and take it out)

array = [0,1,2,3,4,5,6]

result = array.slice(1)
puts result
#=> 1

#The array itself does not change
puts array 
#=> [0,1,2,3,4,5,6]

Part 2-1 (take out multiple elements)

You can also retrieve multiple elements.

The following is the method of "taking out ○ pieces from here".

array = [0,1,2,3,4,5,6]

#Slice the elements for sequence numbers 1 to 4
result = array.slice(1,4)
puts result
#=> 1 2 3 4

You can also use this method to:

#Create a method that outputs the last two characters of an arbitrary character string three times repeatedly

def extra_end(str)
  num = str.length
  right2 = str.slice(num - 2, 2)
  puts right2 * 3
end

extra_end(str)

Get the number of characters in the string with str.length. Since the character string is the same as the array and the beginning is counted from 0, To get the last character of a string, use str.slice (num -1). This time I want to get the last two characters of the string, so set it to str.slice (num --2, 2).

Part 2-2

Another way to retrieve multiple elements There is also a method of "specifying and extracting sequence numbers ○ to X".

array = [0,1,2,3,4,5,6]

#Slice the elements of sequence numbers 1 to 4
result = array.slice(1..4)
puts result
#=> 1 2 3 4

You can also do this.

#Define elements
array = "string"

#Of the sequence number-From 3-Cut out a string in the range of 1
result = array.slice(-3..-1)
puts result
#=> "ing"

The rightmost is -1, and the sequence numbers are counted from right to left as -1, -2, -3 ....

Part 3 slice!

You can change the original array or string by adding! After the slice. (Destructive method)

string = "abcde"

result = string.slice!(2)
puts result
#=> "c"

# "c"Has been removed
puts string
#=> "abde"