Bummer! This is just a preview. You need to be signed in with a Treehouse account to view the entire video.
Start a free Basic trial
to watch this video
In this part of building a simple contact list, we're going to add contacts to our `contact_list` array.
Code Samples
We write the following code in this video. A line by line explanation follows:
def add_contact
contact = {"name" => "", "phone_numbers" => []}
contact["name"] = ask("What is the person's name?")
answer = ""
while answer != "n"
answer = ask("Do you want to add a phone number? (y/n)")
if answer == "y"
phone = ask("Enter a phone number:")
contact["phone_numbers"].push(phone)
end
end
end
answer = ""
while answer != "n"
contact_list.push(add_contact())
end
Code Explanation
First, we create our add_contact method:
def add_contact
We then set up a default contact hash which the method will return. The hash has two keys -- name which is a string and phone_numbers which is an array:
contact = {"name" => "", "phone_numbers" => []}
We then add the name by calling the ask method. The ask method returns a string, which is immediately assigned to the name attribute:
contact["name"] = ask("What is the person's name?")
Next, we set up our answer and loop until the user doesn't want to enter any more phone numbers:
answer = ""
while answer != "n"
answer = ask("Do you want to add a phone number? (y/n)")
If the user answers "y" we ask for a phone number using the ask method. The result is assigned to the phone variable which with then append to the contact["phone_numbers"] array:
if answer == "y"
phone = ask("Enter a phone number:")
contact["phone_numbers"].push(phone)
end
The next lines close the conditional and loop indentation:
end
end
Finally, we set up the answer variable and loop adding contacts until the user is done:
answer = ""
while answer != "n"
contact_list.push(add_contact())
end
-
0:00
Okay, so now that we've got this ask method working let's go ahead and
-
0:05
delete that little test that we did.
-
0:08
Now we'll create a method called add_contact.
-
0:12
And what this is going to do is create a contact which is a hash.
-
0:18
And then it will return that hash.
-
0:24
And our contact we'll say it is going to have a name which
-
0:29
is going to be an empty string, and our contact is going to have phone numbers.
-
0:35
And since they can have more than one phone number that's going to be an array.
-
0:40
And we know that we're going to return this contact.
-
0:46
So now that we have this contact hash setup.
-
0:50
Let's go ahead and get the contacts name.
-
0:55
We do that by saying contact, and then we use the hash key name.
-
1:04
And then we'll set that equal
-
1:06
to the response of asking what the persons name is.
-
1:17
Now you'll see the ask method returns a string which is going to be answer,
-
1:24
so we can call it and assign it all in one go.
-
1:30
So now that we do that we know that we have the name set but
-
1:34
we might not have the person's phone number.
-
1:38
So let's go ahead and ask to enter phone numbers using a while loop.
-
1:44
We'll set the empty answer.
-
1:49
And then we'll say,
-
1:52
while the answer does not equal no, or n.
-
1:57
We'll say,
-
2:03
we ask the the user, do you want to add a phone number?
-
2:07
And we'll give them a little prompt,
-
2:11
saying Y or N, and then if the answer is Y.
-
2:20
We'll ask for the phone number.
-
2:27
Assign that to a variable called phone, and then,
-
2:35
we'll push that answer into the phone numbers array.
-
2:42
So we create our empty hash with default values,
-
2:47
assign a person's name by asking a question.
-
2:50
And then, as long as somebody does not answer no,
-
2:55
we keep asking them to add a phone number/ And
-
2:59
then push that onto our contact phone numbers array.
-
3:04
Now that we have the add contact method, let's go ahead and
-
3:08
loop through and ask people to enter contacts.
-
3:14
We'll use this same pattern that we've been using before.
-
3:17
And we'll say, while the answer does not equal n.
-
3:25
Actually, let's go ahead and take our contact_list array,
-
3:30
and put it closer to this code.
-
3:34
And that's just so we can see it.
-
3:38
So while the answer does not equal no, we will add
-
3:46
to our contact list, the result of the add contact method.
-
3:56
Which returns a contact hash.
-
4:00
And then we can ask the person, If they want to add another.
-
4:11
Let's go ahead and run this and see what happens.
-
4:17
What is the person's name?
-
4:19
Jason.
-
4:20
No I don't want to add a phone number to Jason.
-
4:22
What's the person's name?
-
4:23
Nick.
-
4:25
Do I want to add a phone number?
-
4:27
Yes, 123.
-
4:27
That works.
-
4:28
Do I want to add another phone number?
-
4:31
Yes, 456.
-
4:33
And it's going to keep asking me these questions until I answer no, and
-
4:37
then the program exits.
-
4:39
In our next video,
-
4:40
we're going to format the contact list once we have this all set up.
You need to sign up for Treehouse in order to download course files.
Sign up