[Ruby] What is the slice method? Let's solve the example and understand the difference from slice!

Overview

I have summarized the differences between slice and slice !. I would appreciate it if you could comment and point out any expressions that are easier to understand!

table of contents

--slice and slice! - slice - slice!

--Practice --Problem --Answer (commentary)

--Summary --References

slice and slice!

[Example] Extract the first element from the array and output the original array

point

--Methods that can retrieve specified elements from arrays and strings --Numeric when specifying elements --Starting from 0

slice

array = [0, 1, 2, 3, 4, 5]
num = array.slice(1)

puts num
puts array

#Terminal

#result of puts num
# 1
# =>Extract specified element

# puts array
# 0
# 1
# 2
# 3
# 4
# 5

slice!

--A method with an exclamation mark (!) Is called a destructive method. --Not only extract elements but also change their original shape --Delete the specified element

array = [0, 1, 2, 3, 4, 5]
num = array.slice!(1)

puts num
puts array

#Terminal

#result of puts num
# 1 
# =>The elements that can be taken do not change

# puts array
# 0
# 2
# 3
# 4
# 5
# =>Extracted element (1) has been deleted

Practice

Let's solve the problem using slice using fruits as an example.

problem

Let's create a method that deletes the nth character from any character and outputs that character!

Answer (commentary)

def str_check(string, num)  #String(string)And what number do you want to delete(num)Have received
  string.slice!(num - 1)    #Because it starts from the 0th-You can delete the characters you want to retrieve by doing 1.
  puts string               # slice!You can output characters other than those deleted with
end

#Method call
str_check('apple', 1)
str_check('orange', 2)
str_check('grape', 4)

#Terminal output result

# pple
# oange
# grae

Summary

--Elements can be retrieved from strings and arrays by using the slice method --Specify a number when you want to retrieve an element --Starting from 0th --You can change the shape of the original string or array by using the slice! method.

References

-Ruby 3.0.0 Reference Manual [slice]

-Ruby 3.0.0 Reference Manual [slice!]