Ruby Arrays

[MUSIC] 0:00 Hi, I'm Jason. 0:04 Let's start talking about arrays in Ruby. 0:06 So far, some basic types that we've learned about are strings and numbers. 0:09 Strings let us work with textual data in our programs, and 0:14 numbers with numerical data. 0:18 Let's say that we wanted to create a shopping list. 0:21 Inside of the shopping list, 0:24 our grocery items could be something like milk, eggs, and bread. 0:25 We could store that list in a string separated by commas. 0:30 Or we could use three different strings called something like item one, 0:34 item two, item three, and so on. 0:38 However, Ruby gives us a type specifically to work with that kind of data. 0:41 We could use an array. 0:46 An array is a container of data. 0:49 You can think of it as a list. 0:52 We could store all of our different grocery items inside of the array. 0:54 Arrays can store any type of thing that we have access to in Ruby. 0:59 Let's see how to make an array now using WorkSpaces. 1:04 So I have gone in and created a new Ruby workspace. 1:08 Now, over here in the console, going to drag this up. 1:14 And we're going to launch IRB by typing irb and press Enter. 1:19 Now let's go ahead and create our very first array. 1:25 We'll do that by typing the name of the variable, 1:30 in this case we'll say we wanna create a grocery list. 1:33 Now I'm going to type a space and the equals sign, another space, and 1:38 then capital a, y, a dot, and the word new. 1:43 This will create a new array, initialized to the variable called grocery list. 1:51 Now, right below, you'll see we have an equal sign, and 1:57 a greater than sign, which is going to be the return value. 2:01 And the return value is an open bracket, and then a closed bracket. 2:05 That's Ruby's sign for an array. 2:09 Now we can take a look at this grocery list item and it returns the same thing. 2:13 There’s another way that we can create an array. 2:19 And that is to use the brackets themselves. 2:24 So, we can type an open square bracket and then a closed square bracket and 2:26 we get the same thing. 2:30 Now this is useful, but 2:32 it’s not as useful as having a grocery list with items inside of it. 2:34 Lets go ahead and create a grocery list array with our items already in it. 2:40 So we'll put three items in here. 2:48 The way we add items to an array when creating it, 2:51 is to put the items inside of the brackets, separated by commas. 2:54 So right here, I've opened the bracket and will put the string milk, and 3:00 then we'll also add eggs and bread into this array. 3:05 Now we separate the items by a comma. 3:09 So in this case, we have milk as an item, 3:13 and then a comma, eggs, another comma, and bread. 3:16 We don't put a closing comma before the closing square bracket. 3:20 Now when we look at the grocery list, it has the same thing as an empty array, 3:27 except the items are inside. 3:31 Now we're not limited to just strings. 3:35 We could add numbers as well. 3:38 And you'll notice the numbers don't have quotes around them, 3:41 just like when we were working with strings and numbers by themselves. 3:44 Now another way to create an array, if we wanted to create an array of just strings, 3:50 we could use the %w syntax. 3:57 And then we don't have to surround our strings with quotes. 4:01 Now if we look at our grocery list, it has the same thing as if we did 4:09 surround it with quotes, and use the square bracket notation. 4:14 Another thing that we can do is use an uppercase W. 4:21 Now just like when we were printing things out with strings and 4:26 having them interpolated, using a capital W will allow us to do interpolation. 4:29 So I have assigned a variable called item equal to a string called milk. 4:38 Now, when I create this grocery list array, using a capital W, 4:43 item will be interpolated. 4:47 And the array comes back with a string of milk, another string of eggs, and 4:49 another string of bread. 4:54 Try both methods of creating arrays now, using WorkSpaces. 4:58