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Ruby Ruby Collections Ruby Arrays Adding Items to Arrays

J Quinn
J Quinn
2,439 Points
Posted by J Quinn
J Quinn
2,439 Points

How do I use .unshift?

Trying to get "carrots" to front of the array. What am I doing wrong?

array.rb 
grocery_list = ["milk", "eggs", "bread", "carrots"]
grocery_list.unshift ("carrots")

1 Answer

Marco van Vemden
Marco van Vemden
12,553 Points
Marco van Vemden
Marco van Vemden
12,553 Points

Hi J, The .unshift method adds a new item to the beginning of the array, but the method does not remove the last item from the array. You could use the .pop method for that. Here are two solutions that have the same output:

# Add to beginning, and remove last item
grocery_list = ["milk", "eggs", "bread", "carrots"]
grocery_list.unshift ("carrots")
grocery_list.pop()
puts grocery_list

# Rotate only the last element (-1), so it becomes first
grocery_list = ["milk", "eggs", "bread", "carrots"]
grocery_list.rotate!(-1)
puts grocery_list