remove first element from array ruby code example

Example 1: ruby delete first element of array

a = [0,1,2,3]

a.drop(1)
# => [1, 2, 3] 

a
# => [0,1,2,3]

Example 2: ruby array remove by index

a= [1,1,1,2,2,3]
delete_list = [1,3]
delete_list.each do |del|
    a.delete_at(a.index(del))
end