• How does a variable of a primitive type differ from a reference variable?
• What does the operator new do
• Consider the following statements:

String str = "Going to the amusement park"

char ch;

int len;

int position;

a. What value is stored in ch by the following statement? ch = str.charAt(0);

b. What value is stored in ch by the following statement? ch = str.charAt(10);

c. What value is stored in len by the following statement? len = str.length();

d. What value is stored in position by the following statement? position = str.indexOf('t');

e. What value is stored in position by the following statement? position = str.indexOf("park");

• Which of the following statements are valid? If they are invalid, explain why.

b. System.out.println(cube(num1, num3, num2));

c. System.out.println(cube(6.0, 8.0, 10.5));

d. System.out.println(num1 + " " + num3);

e. System.out.println(cube(num1, num3));

f. value = cube(num1, int2, num3);

g. value = cube(7, 8, 9);

• Why do users prefer a GUI over a nongraphical user interface?
•  Write necessary statements to create the following GUI components:

a. A JLabel with the text string "Enter the number of courses"

b. A JButton with the text string "Run"

c. The title "Welcome Home!" for an existing window

d. A width of 200 pixels and a height of 400 pixels for an existing window

•  Correct the syntax errors in the following program:

public class RTwo extends JFrame

{

public RTwoProgram()

{

private JLabel length, width, area;

setTitle("Good day Area");

length = JLabel("Enter the length);

width = JLabel("Enter the width);

area = JLabel("Area: ");

containerPane = ContentPane();

pane.setLayout(GridLayout(4,1));

setSize(WIDTH,HEIGHT);

setVisible();

setDefaultCloseOperation(EXIT_ON_CLOSE);

}

public static void main(String args[])

{

RTwoProgram R2 = new RTwoProgram();

}

}
9. What is the output of the following program segments?

a. if (6<2*5)

System.out.print("Hello");

System.out.print(" There");

b. if ('a' > 'b' || 66 > (int)('A'))

System.out.println("#*#");

c. if (7<=7)

System.out.println(6 - 9 * 2 / 6);

d. if { (7<8)

System.out.println("2 4 6 8");

System.out.println("1 3 5 7); }

e. if (5 < 3)

System.out.println("*");
else if

(7 == 8) System.out.println("&");

else

System.out.println("tiny_mce_markerquot;);

• . Write Java statements that output Democrat if the party affiliation code is 'D', Republican if the party affiliation code is 'R', and other otherwise.

• Suppose that you have the following declaration:

int j = 0;

The output of the statement
if ((8 > 4) || (j++ == 7)) System.out.println("j = " + j);

is

j=0

while the output of the statement

if ((8 > 4) | (j++ == 7)) System.out.println("j = " + j);

is

j = 1

Explain why.

•  Suppose the input is 5. What is the value of alpha after the following Java code executes? (Assume that alpha is an int variable and console is a Scanner object initialized to the keyboard.)

alpha = console.nextInt();

switch (alpha)

{

case 1:

case 2:

alpha = alpha + 2;

break;

case 4:

alpha++;

case 5:

alpha = 2 * alpha;

case 6: alpha = alpha + 5; break;

default:

alpha--;
}

•  Suppose the input is 6. What is the value of a after the following Java code executes? (Assume that all variables are properly declared.)

a = console.nextInt();
if (a > 0)

switch (a)
{
case 1:

a = a + 3;
case 3:

a++;

break;
case 6:

a = a + 6;
case 8: a

= a * 8;

break;

default:

a--;

}

else

a = a + 2;

•  The following program contains errors. Correct them so that the program runs and outputs w =21.

public class Mystery

{

static final int SECRET = 5;

public static void main(String[] args)

{

int x, y, w, z;

z = 9;

if z > 10

x = 12; y = 5, w = x + y + SECRET;

else

x = 12; y = 4, w = x + y + SECRET;

System.out.println("w = " + w);

}

}

•  Name two GUI input components.