Heads up! To view this whole video, sign in with your Courses account or enroll in your free 7-day trial. Sign In Enroll
Preview
Start a free Courses trial
to watch this video
Let's walkthrough the solution to the second code challenge.
For this challenge,
we need to use the forEach method to copy
0:00
only the first 2 characters of
each string in the days array.
0:03
And store the abbreviations in
the dayAbbreviations array.
0:07
Like I did earlier,
I'm going to copy and paste the code for
0:11
this challenge into the Atom text editor
in order to make the code easier to read.
0:14
So the days array contains seven strings,
one string for each day of the week.
0:22
And what we want to end up with is an
abbreviation for each of those strings or
0:28
each of those days.
0:32
So Su for Sunday.
0:34
Mo for Monday and so on.
0:37
Let's look at my solution.
0:39
Again, I started by adding the call for
each method.
0:41
And then, the anonymous call back
function using arrow function syntax.
0:45
So, days.forEach.
0:49
And, I use day for
the current value parameter name.
0:54
Day, and then a fat arrow.
0:57
Then I added a set of curly
braces to define a code block.
1:00
Let's add a variable for
the dayAbbreviation.
1:04
So const dayAbbreviation.
1:06
To get the first two characters of each
day string, I used the slice method.
1:12
So day.slice.
1:16
Now, you could also use substring.
1:19
Or substr.
1:22
Both of those methods
would also work fine.
1:24
I'm going to go ahead and
switch back to the slice method.
1:27
The first parameter for
the slice method is the begin index.
1:31
The zero based index at the string
extraction should begin with.
1:34
The second parameter is the end index.
1:39
The index that the string
extraction should end with.
1:42
It's worth noting that the character
at this index won't be included.
1:45
Let's take a look at the string for
Sunday.
1:49
So S is at an index of 0.
1:52
U is at an index of 1.
1:55
And n is at an index of 2.
1:58
So we want to extract Su, but not n.
1:59
So with the slice method,
we'll supply the 2.
2:05
Meaning that we want to select up to but
not including the index of 2.
2:08
Now that I have my dayAbbreviation, I just
pushed it onto the dayAbbreviations array.
2:14
So dayAbbreviations.push(dayAbbreviation).
2:20
And that's my solution.
2:26
Now, we can leave it just as it is,
or we could simplify it.
2:28
We can do that by eliminating the
intermediate variable, (dayAbbreviation).
2:33
To do that, let's cut this code and place
it inside of the call to the push method.
2:38
Then we can eliminate this line of code.
2:44
And we can actually eliminate
the code block itself.
2:47
There.
2:51
That looks a little cleaner, doesn't it?
2:53
Ready for the next challenge?
2:55
We'll see you in a bit with my solution.
2:56
You need to sign up for Treehouse in order to download course files.
Sign up