COMP 14: Midterm Review

June 8, 2000Nick Vallidis

Announcements

Midterm is tomorrow!

Assignment P4

Just want to go over it to make sure you all understand...

Instantiating objects

We do this with the keyword new

Examples:String name;

name = new String("Vallidis");

Die myDie;

myDie = new Die(6);

packages

A package is a group of classes

That's it. In Java, each class has its own .java file and all the .java files in a directory are one package.

Assignment operators

mult += value

is just the same thing as:mult = mult + value

This is just a shortcut so you don't have to type mult twice!

You can replace + with any of the normal math operators: -, /, %, etc.

Equivalence of loops

All loops have the same four parts: initialization condition statements (the loop body) increment (the loop update -- it doesn't

have to be an increment specifically)As a result, you can convert between

loop types.

Equivalence of loops

for (initialization; conditon; update)body;

initialization; initialization;while (condition) do{ {

body; body;update; update;

} }while (condition);

Nested if statements

What's up with this?

if (x < 3)

if (y > 2)

System.out.println("yay!");

else

System.out.println("x >= 3");

Nested if statements

write nested ifs to do the following: you have one integer x when 0<=x<5 print "low" when 5<=x<10 print "medium" when 10<=x<15 print "high" for any other value of x don't do anything

------------------------------------------------------Can you do this as a switch statement?

nested loops

what does this code do?int i, j;

for (i=1; i<=5; i++)

{

for (j=i; j>=1; j--)

System.out.print("*");

System.out.println();

}

nested loops

Write code to print out a person's name 5 times and then ask if they want to do it again. If they do, then print their name again 5 times (response can be string or integer)

Assume the name has already been read and has this declaration:

String name;