Welcome to AP Computer Science A. If you are a student in the class, the first thing you need to do (and which we should have done in class) is set up your GitHub account.
Once you have a GitHub account, click “Log in to GitHub” below to proceed.
If you don’t have a GitHub account yet, please create one and then log in here for further instructions.
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This is a tool for the AP Computer Science A class at Berkeley High School. It is intended to provide a simple environment for experimenting with Javascript without all the complexities of a full development environment such as ReplIt or Glitch which we may use later in the year.
It is also designed to take advantage of the browser’s ability to run Javascript natively. It does not need access to a server to run code making in extremely responsive even if the Wifi is flaking out.
Finally, under the covers it is saving work to a GitHub repository in a very simplified workflow that does not depend on immediately learning any git commands. Code written in this environment for each assignment is saved to a directory and branch specific to that assignment each time it is saved. Thus when the assignment is done, it is easy to go to GitHub and create a PR containing just the work on that assignment which can then be commented on and worked on further before it is turned in and merged to main.
You're all set! You don't need to worry about this yet but we have successfully created a GitHub repository for your work:
You can get to it any time by clicking on your GitHub username at the top-right of the screen.
Write a method that takes a single String argument and
returns a String consisting of just the first character
of the argument.
Write a method that takes a single String argument and
returns a String consisting of just the last character
of the argument.
Write a method named pair that takes two
String arguments and returns a single
String consisting of the two arguments separated by the
word and.
Write a method that takes two String arguments and
returns a boolean indicating whether the first
String is longer than the second.
Write a method named upDown that takes a single
String argument and returns a
String consisting of the original
String all in upper case concatenated (“smooshed
together”) with the String all in lower case.
Write a method named contains that takes a two
String arguments and returns true if the
second String is contained in the first and false if it
is not.
Write a method named slug that takes three
String arguments and returns a “slug” consisting of the
three Strings joined together with hyphens and all in
lower case. For instance
slug("Foo", "Bar", "BAZ") would return
"foo-bar-baz".
Write a method named simplePigLatin that takes two
arguments, a String containing a single word and a
number indicating the index of the first vowel in the word, and
returns the word translated into Pig Latin.
Write a method that takes a single String argument and
returns a String consisting of the argument in
capitalized form, i.e. with the first letter in uppercase and the
rest of the letters in lower case.
Write a method that takes a two arguments, a String and
an int and returns a String consisting of
the character in the first argument at the index given by the
second.
Write a method that takes a single String argument and
returns the first half of the String. (If the
String has an odd number of characters it doesn’t
matter whether or not you include the extra character.) For instance
the first half of "foobar" is "foo" but if
the argument was "fooquux" then either
"foo" or "fooq" would be acceptable return
values.
Write a method that takes a single String argument and
returns the second half of the String. (If the
String has an odd number of characters it doesn’t
matter whether or not you include the extra character.) For instance
the second half of "foobar" is "bar" but
if the argument was "fooquux" then either
"quux" or "uux" would be acceptable return
values. For maximum style points write this method and
firstHalf so that
firstHalf(s) + lastHalf(s) gives you back
s.
Write a method that takes a two String arguments and
returns a String consisting of the characters of the
first argument up to but not including the first occurrance of the
second argument in in the first. You can assume the first
String contains the second somewhere.
Write a method that takes a single String argument
which will consist of a full name in the form a first name, a space,
and a last name and returns a String containing just
the first name.
Write a method that takes a single String argument
which will consist of a full name in the form a first name, a space,
and a last name and returns a String containing just
the last name.
Write a method that takes two String arguments and
returns true if, and only if, the first argument starts with the
second argument.
Write a method that takes two String arguments and
returns true if, and only if, the first argument ends with the
second argument. You can assume the first argument is longer than
the second.
Write a method that takes a single String argument and
returns a String consisting of the the middle 50% of
the argument, i.e. the original String with the first
and last quarter removed.
Write a method that takes a single String argument and
returns a String consisting of two characters, the
uppercase version of the last character of the argument
String and the lowercase version of that same
character.
Write a method that takes a two arguments, a String and
an int and returns a two-character String
consisting of the character in the first argument at the index given
by the second, once in upper case and then in lower case.
Write a method that takes a single String argument that
will be at least two-characters long and returns a two-character
String consisting of just the first and last characters
of the String.
Write a method that takes a single String argument and
returns a String consisting of the second half of the
original String followed by the first half. If the
String is an odd number of characters it doesn’t matter
whether the extra character goes with the front or the back.
Write a method that takes a single String consisting of
a first and last name separated by a space and returns a
String with the first and last name separated by a
space but each capitalized.
Write a method that takes a single String argument
which will consist of a full name in the form a first name, a space,
and a last name and returns a String containing the
person’s initials, i.e. the first letter of their first name
followed by the first letter of their last name.
This is a test of writing methods that compute using
Strings (and a few booleans and numbers)
with the methods covered in Unit 2 and the + operator.
As is usually the case when writing methods, you should be on the
lookout for opportunities to implement methods in terms of other
methods you’ve already written, especially in the later problems.
The questions are roughly arranged from easier to harder and the later ones are worth more. So if you get stuck on an early question, probably best to move on and come back to it.
Quick reference
String s = "Foo";s + s ⟹ "FooFoo"s.substring(0, 1) ⟹ "F"s.length() ⟹ 3s.toUpperCase() ⟹ "FOO"s.toLowerCase() ⟹ "foo"s.indexOf("o") ⟹ 1Pro tip: when you click one of the method buttons, the name of the method is copied to your clipboard so you can paste it into your code, saving typing and avoiding spelling errors. Finally, click the black triangle at the start of these instructions to collapse them and have more room to code.