Midterm 2 Information

Time: Thursday, 4/8, 5-7pm (unless you’ve contacted me about a conflict)

Place: 145 Birge

Bring: Your student ID and some pencils

What’s the exam format?

The format will be the same as last time. This exam covers primarily the material after the first midterm. But as you can tell, a lot of this material depends on earlier concepts, so it’s not like you can totally forget everything you’ve studied already.

How can you prepare?

The true-false and multiple choice questions focus on Java terminology and facts from chapters 5,6,8, and 9, and on understanding small pieces of code. The written section will require you to write small pieces of code that solve specific problems, or possibly to write explanations of concepts. Expect questions related to any assignments and class examples you’ve seen so far, and about all the term definitions and Java rules that we talked about in class since the first exam. Here are some suggestions for studying:

• Write out definitions for each term below.
• Go through the quizzes on our website and take turns explaining the answers.
• Go through the example programs on our site and understand how they work.
• Answer the “Quick Check” questions throughout the book chapters.
• Do the review exercises on the back and the lab exercises from Thursday 4/1.
• Ask questions, either at the in-class review session or by email.

Terms:

sequential execution

control statement

selection statement

repetition statement

boolean expression

relational operator

boolean operator

arithmetic exception

null pointer exception

short-circuit evaluation

flag

nested statements

increment/decrement operators

dangling else problem

DeMorgan's law

defensive programming

count-controlled loop

sentinel-controlled loop

priming read

infinite loop

overflow error

off-by-one error

pretest loop

posttest loop

control variable

ASCII

Unicode

character

string

out-of-bounds exception

exception thrower

exception catcher

exception propagator

checked exception

unchecked exception

runtime exception

1) Evaluate the following boolean expressions:

a) 6 == 6 || x < y

b) 2 < 4 && (false || 5 <= 4)

c) x <= y && !(z != z) || x > y

d) x < y || z < y && y <= z

2) Fill in the method so it returns true if at least two of the parameters are true.

public boolean areAnyTwoTrue(boolean a, boolean b, boolean c) {

}

3) What's the value of x after these loops?

int x=0, i=0; int x = 0;

while (i < 6) { do {

x += i; x -= 10;

i += 2; } while (x > 0);

}

4) Fill in the method so it prints the location of each Trash object in the TrashList.

public void printTrash(TrashList list) {

}

5) Fill in the method so it inputs a double without ever throwing an IOException or a NullFormatException.

public double getDouble(BufferedReader buf) {

}

6) Fill in the method so it returns a new String containing only every other letter from the parameter String.

public String alternate(String str) {

}