Final Exam (part 1)

Question 1

The compiler generates bytecode even if the program has syntax errors. T/F

Answer 1

False

Question 2

Java was originally developed by a team led by James Gosling at Sun Microsystems. T/F

Answer 2

True

Question 3

One byte has ____ bits.

Answer 3

8

Question 4

The JDK command to compile a class in the file Text.java is _____.

Answer 4

javac Test.java

Question 5

The command to compile a class in the file Test.java is ____.

Answer 5

javac Test.java

Question 6

______ is a technical definition of the language that includes the syntax and semantics of the java programming language.

Answer 6

Java JDK

Question 7

The extension name of a java source code file is _____.

Answer 7

.java

Question 8

A block is enclosed inside _____.

Answer 8

braces

Question 9

To assign a double variable d to a float variable x, you write ______.

Answer 9

x = (float)d;

Question 10

-25 % 5 is _____.

Answer 10

0

Question 11

To improve readability and maintainability, you should declare _____ instead of using literal values such as 3.14159.

Answer 11

constants

Question 12

To assign a value 1 to variable x, you write ______.

Answer 12

x = 1;

Question 13

Which of the following assignment statements is illegal?
float f = -34;
int t = 23;
short s = 10;
float f = 34.0;

Answer 13

float f = 34.0;

Question 14

Any assignment statement can be used as an assignment expression. T/F

Answer 14

True

Question 15

If you attempt to add an int, a byte, a long, and a double, the result will be a _____ value.

Answer 15

double

Question 16

System.exit(0) can be used to terminate the program. T/F

Answer 16

True

Question 17

Suppose x = 10 and y = 10. What is x after evaluating the expression (y > 10) && (x– > 10)?

Answer 17

10

Question 18

In Java, the word true is _____.

Answer 18

a Boolean literal

Question 19

Which of the following expression is equivalent
to (x > 1)?
x >= 1
!(x <= 1)
!(x = 1)
!(x < 1)

Answer 19

!(x <= 1)

Question 20

Assume x = 4, which of the following is true?
!(x == 4)
x != 4
x == 5
x != 5

Answer 20

x != 5

Question 21

_______ are short-circuit operators.
&&

||
!

Answer 21

&&
||

Question 22

Which of the following is a possible output for (int)(51 * Math.random())?
0
50
100
500

Answer 22

0
50

Question 23

“smiles”.substring(1, 5) returns “mile”. T/F

Answer 23

true

Question 24

An int variable can hold ____.
‘x’
120
120.0

Answer 24

‘x’
120

Question 25

Which of the following is the correct expression of character 4?
4
“4”
‘\0004’

Answer 25

‘4’

Question 26

To obtain the sine of 35 degrees, use ____.
Math.sin(35)
Math.sin(Math.toRadians(35))
Math.sin(Math.toDegrees(35))
Math.sin(Math.toRadian(35))
Math.sin(Math.toDegree(35))

Answer 26

Math.sin(Math.toRadians(35))

Question 27

Given two Strings s1 = “Welcome to Java” and s2 = “Programming is fun”, which of the following is true?
s1.equals(s2)
s2.equals(s1)
s1.contains(s2)
s2.contains(s1)
!s1.contains(s2)

Answer 27

!s1.contains(s2)

Question 28

Suppose i is an int type variable. Which of the following statements display the character whose Unicode is stored in variable i?
System.out.println(i);
System.out.println((char)i);
System.out.println((int)i);
System.out.println(i + “ “);

Answer 28

System.out.println((char)i);

Question 29

Write one statement that prints out “No pain, no gain.” The output need to be in two lines as:
No pain,
no gain.
(note: there is a tab space in front of no gain)

Answer 29

System.out.println(“No pain,\n\tno gain.”);

Question 30

Write an if-else statement to print out “EVEN” if x is even; print out “ODD” if x is odd. Here x is an int type variable that has been initialized

Answer 30

if(x % 2 == 0) System.out.println(“EVEN”);
else System.out.println(“ODD”);

Question 31

Write a line of code to declare a Scanner object named keyboard.

Answer 31

Scanner keyboard = new Scanner(System.in);

Question 32

Write an if-else statement to print out “Excellent” if the student’s score is 90 or above, “Good” if the student’s score is 80 to 89, “Word harder” otherwise. Assume score is an int type variable that has been initialized.

Answer 32

if(score >=90) System.out.println(“Excellent”);
else if(score >= 80) System.out.println(“Good”);
else System.out.println(“Word harder”);

Question 33

Write a switch statement to print out “Excellent” if the student’s grade is A; “Good” if the student’s grade is B; “Word harder” otherwise. Assume grade is a char type variable that has been initialized.

Answer 33

switch(grade) {
case ‘A’: System.out.println(“Excellent”);
break;
case ‘B’: System.out.println(“Good”);
break;
default: System.out.println(“Word harder”);
break;
}

Question 34

Write one expression that returns true if and only if char c is an arithmetic operator, i.e. +, -,*,/ or %.

Answer 34

c == ‘+’ || c == ‘-‘ || c == ‘’ || c == ‘/’ || c == ‘%’
or
“+-/%”.indexOf(c) != -1

Question 35

Write one expression that returns true if and only if String s doesn’t contain lower case English letter.

Answer 35

s.equals(s.toUpperCase())

Question 36

Write one line of code to print out the length of String greeting. Assume that greeting has been declared and initialized.

Answer 36

System.out.println(greeting.length());