1. Let Account be the bank account class discussed. What balance will be stored in acct1, acct2, and acct3 after the following statements have been executed?
Account acct1 = new Account(200.00);
Account acct3 = new Account(200.00);
Account acct2= acct3;
acct1.withdraw(50.00);
acct2.deposit(100.00);
acct3.deposit(50.00);
2. Suppose that f1 and f2 are Fraction objects, where Fraction is the class described in Chapter 3. Write a statement that adds f1 and f2 and stores the result in a variable named f3. (The method that adds fractions is named add.) You may assume that f3 has already been declared as a Fraction variable.
3. Show the output of the following program.
public class Problem47 {
public static void main(String[] args) {
String msg1 = "CSc 226J is available next quarter";
String msg2 = "Get a grip!";
String msg3 = "Now, let's eat!";
String sub1 = msg1.substring(7, 15);
String sub2 = msg2.substring(6, 8);
String sub3 = msg3.substring(11, msg3.length());
System.out.println(sub1.substring(0, 1) +
sub1.substring(5, sub1.length()) +
sub1.substring(1, 5) +
sub2 + sub3);
}
}
Output = Java is great!
4. What will be printed when the following statements are executed?
Account acct1 = new Account(1000.00);
Account acct2 = new Account(1000.00);
if (acct1 == acct2)
System.out.println("Equal");
else
System.out.println("Not equal");
5. Following is a part of the source codes for NFLTeam3 and NFLGameDay3 classes. To make sure one can run the following NFLGameDay3 and print the meaningful win/loss number of the teams on the screen, please write necessary methods to finish the class of NFLTeam3 (hints: at least 3 more methods are needed).
public class NFLTeam3{
privateint win;
privateint loss;
private String name;
public void winAgame(){
win++;
}
public void winAgame(NFLTeam3teamB){
win++;
teamB.lossAgame();
}
public void lossAgame(){
loss++;
}
}//end of NFLTeam3 class definition
public class NFLGameDay3 {
public static void main (String [] args){
NFLTeam3 falcons = new NFLTeam3("falcons");
NFLTeam3 steelers = new NFLTeam3("steelers");
falcons.lossAgame(steelers);
System.out.println (falcons);
System.out.println (steelers);
}
}
6. For each of the following code segments, how many times will ``Hello World'' be printed out when the code segment is executed? Briefly explain each answer. Be careful; some of these are tricky!
a)int i;
for (i = 0; i <= 10; i++)
System.out.println("Hello World");
b)int i;
for (i = 1; i < 10; i++) {
if ( i % 3 == 0 )
System.out.println("Hello World");
}
c)int i;
for (i = 1; i <= 25; i++);
System.out.println("Hello World");
7. Of the following if statements, which one correctly executes three instructions if the condition is true?
A) if (x < 0)
a = b * 2;
y = x;
z = a - y;
B) {
if (x < 0)
a = b * 2;
y = x;
z = a - y;
}
C) if { (x < 0)
a = b * 2;
y = x;
z = a - y ;
}
D) if (x < 0)
{
a = b * 2;
y = x;
z = a - y;
}
E) B, C and D are all correct, but not A