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[6 pts]
Given the two classes below, what will main display?
public class Worker {
private String job;
public Worker(String s) {
job = s;
}
public void setJob(String s) {
job = s;
}
public String getJob() {
return job;
}
}
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public class Main {
public static void main(String[] args) {
Stack<Worker> s = new Stack<Worker>();
Worker gwb = new Worker("president");
Worker bho = new Worker("senator");
Worker you = new Worker("student");
s.push(gwb);
s.push(bho);
s.push(you);
gwb.setJob("none");
you = bho;
you.setJob("pres");
bho = gwb;
System.out.println(s.pop().getJob());
System.out.println(s.pop().getJob());
System.out.println(s.pop().getJob());
}
}
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[8 pts] Suppose we remove from the heap whose tree diagram is below. What will its tree diagram then be?
[8 pts] Suppose we add 3 into the heap represented by the array below. What will the array then be?
[8 pts]
Suppose that we have a Manager class that implements the
ActionListener interface.
The class has a no-parameter constructor.
For each of the following fragments, indicate whether it would
compile (at least one would), and for those that would not,
indicate what the compiler would complain about.
| a. |
void reg(JButton b, Manager m) {
b.addActionListener(m);
}
void run() {
JButton b = new JButton("OK");
reg(b, new Manager());
}
| b. |
void reg(JButton b, ActionListener m) {
b.addActionListener(m);
}
void run() {
JButton b = new JButton("OK");
reg(b, new Manager());
}
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| c. |
void reg(JButton b, Manager m) {
b.addActionListener(m);
}
void run() {
JButton b = new JButton("OK");
reg(b, new ActionListener());
}
| d. |
void reg(JButton b, ActionListener m) {
b.addActionListener(m);
}
void run() {
JButton b = new JButton("OK");
reg(b, new ActionListener());
}
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