- Build a Grocery List Program: Part 1 3:15
- Create a Method That Returns a Hash 1 objective
- Build a Grocery List Program: Part 2 3:58
- Create a Method That Returns an Array 1 objective
- Build a Grocery List Program: Part 3 3:47
- Method Returns with Hashes and Arrays 1 objective
- Build a Grocery List Program: Part 4 4:17
- Working with Hashes That Contain Arrays 1 objective
- Ruby Collections: Review 6 questions
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Build a Grocery List Program: Part 3
3:47Now that we know how to use arrays and hashes, we're going to build a small program that makes a grocery list for us. In this video, we'll modify our program to output our list for us.
Okay, so when we last left off,
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we have added onto our shopping list
after calling the add_list_item method.
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And that put list items
into an array of hashes.
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So now that we have all of this done,
let's go ahead and print out our list.
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And we'll create a new method to do that.
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So what I'm gonna do is click up in here
and create a method called print_list.
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And we'll pass in as an argument
the list that we want to print.
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So we know that our list has a name.
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So let's go ahead and
print that out as the first item here.
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Now we do that by using
string interpolation.
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Now we know that the list
name is a string.
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And we access the value of
that by calling list['name'].
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Since it's a string, string
interpolation will work just the same.
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It's just like calling any other variable.
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Now, let's go ahead and create a line.
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That'll just be four dashes.
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Now what we want to do is print
out the items in the list.
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Now we know that the list items
is an array containing hashes.
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What we can do is use
a method called each.
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We'll get into this method a little
bit more in an upcoming course,
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but for right now,
we'll just follow along.
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So we call the method each.
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Now when we call the method each, we use
this new piece of Ruby syntax called
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a block, and then pass in an argument.
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Blocks are written by typing either
curly braces or the words do and end.
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So what this is going to do is take each
item in this array of list items and
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assign it to a variable called item.
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And now, we can print out the item
name and the item quantity.
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Now remember the list items
array is an array of hashes.
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So let's go ahead and
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print out the item['name'] because we want
to know what the name is of the item.
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And we'll also print out quantity and
the item's quantity.
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And then we'll print
out another separator.
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Okay.
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Now that we have this,
let's go ahead and call print_list and
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send in our shopping list.
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Let's run this and see what happens.
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The list name is Groceries,
that item that we're adding is Milk, and
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we're adding one thing of milk.
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Oh, it looks like we
have an error on line 26.
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And the error is, no implicit
conversion of fixnum into String.
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So what we have to do is tell Ruby that
we want this number to be a string.
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And we use the to_s method to do that.
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Let me clear my screen here.
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And we'll run this again and
see what happens.
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Now we're going to add Milk and
one thing of Milk.
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And now here is our grocery list.
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Alright, that looks good, but
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we're going to clean this up
a little bit more in the next video.
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