The reverse!
method in Ruby can be used to permanently reverse an array. A similar method, reverse
, only returns a copy of the reversed array but does not change the array permanently.
array.reverse!
This method does not take any parameters.
The original array is reversed and returned.
In the example below, we create some arrays and demonstrate the use of reverse!
to reverse the arrays permanently.
# creating array instances array1 = [1, 2, 3, 4, 5] array2 = ["a", "b", "c", "d", "e"] array3 = ["Javascript", "Python", "Java", "C++", "Ruby"] # printing their reverse form using `reverse()` method puts "#{array1} in reverse = #{array1.reverse!}" puts "#{array2} in reverse = #{array2.reverse!}" puts "#{array3} in reverse = #{array3.reverse!}" # Confirm they are reversed permanently puts "#{array1}" # [5, 4, 3, 2, 1] puts "#{array2}" # ["e", "d", "c", "b", "a"] puts "#{array3}" # ["Ruby", "C++", "Java", "Python", "Javascript"]
In the code above, from lines 13 to 16, we see that the arrays were permanently reversed after calling the reverse!
method.
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