Java Practice 1

________is a technical definition of the language that includes the syntax and semantics of the Java programming language.

Which JDK command is correct to run a Java application in ByteCode.class?

________ is a software that interprets Java bytecode.

________ is an operating system.

________is interpreted.

________ contains predefined classes and interfaces for developing Java programs.

Which of the following statements is correct?

________provides an integrated development environment (IDE) for rapidly developing Java programs. Editing, compiling, building, debugging, and online help are integrated in one graphical user interface.

Java was developed by ________.

Java compiler translates Java source code into ________.

Suppose you define a Java class as follows:

public class Test {

}

In order to compile this program, the source code should be stored in a file named

________is Architecture-Neutral.

Java ________ can run from a Web browser.

________ is the brain of a computer.

The expression "Java " + 1 + 2 + 3 evaluates to ________.

If a program compiles fine, but it produces incorrect result, then the program suffers ________.

Which of the following code displays the area of a circle if the radius is positive?

What is 1 + 1 + 1 + 1 + 1 == 5?

Suppose x is 1. What is x after x += 2?

Which of the following expression results in a value 1?

What is x after the following statements?

int x = 1;
x *= x + 1;

What is the result of 45 / 4?

Analyze the following code:

boolean even = false;
if (even = true) {
System.out.println("It is even!");
}

What is i printed in the following code?

public class Test {
public static void main(String[ ] args) {
int j = 0;
int i = j++ + j * 5;
System.out.println("What is i? " + i);
}
}

25 % 1 is ________.

How many times will the following code print "Welcome to Java"?

int count = 0;
while (count < 10) {
System.out.println("Welcome to Java");
count++;
}

Suppose x is a char variable with a value 'b'. What is the printout of the statement System.out.println(++x)?

Analyze the following code:

Code 1:

boolean even;

if (number % 2 == 0)
even = true;
else
even = false;

Code 2:

boolean even = (number % 2 == 0);

Which of the following is the correct expression that evaluates to true if the number x is between 1 and 100 or the number is negative?

Suppose x=10 and y=10 what is x after evaluating the expression (y > 10) && (x++ > 10)?

What is 1.0 + 1.0 + 1.0 + 1.0 + 1.0 == 5.0?

What is the printout of the following switch statement?
char ch = 'a';
switch (ch) {
case 'a':
case 'A':
System.out.print(ch); break;
case 'b':
case 'B':
System.out.print(ch); break;
case 'c':
case 'C':
System.out.print(ch); break;
case 'd':
case 'D':
System.out.print(ch);
}

What is y after the following switch statement is executed?

x = 3;
switch (x + 3) {
case 6: y = 0;
case 7: y = 1;
default: y += 1;
}

What is the printout of the following switch statement?

char ch = 'b';

switch (ch) {
case 'a':
System.out.print(ch);
case 'b':
System.out.print(ch);
case 'c':
System.out.print(ch);
case 'd':
System.out.print(ch);
}

Analyze the following program fragment:

int x;
double d = 1.5;

switch (d) {
case 1.0: x = 1;
case 1.5: x = 2;
case 2.0: x = 3;
}

Analyze the following code.

boolean even = false;
if (even) {
System.out.println("It is even!");
}

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

The "less than or equal to" comparison operator in Java is ________.

What is the output of the following code?

char ch = 'F';
if (ch >= 'A' && ch <= 'Z')
System.out.println(ch);

________ is the code with natural language mixed with Java code.

The statement System.out.printf("%3.1e", 1234.56) outputs ________.

Suppose income is 4001, what is the output of the following code:

if (income > 3000) {
System.out.println("Income is greater than 3000");
}
else if (income > 4000) {
System.out.println("Income is greater than 4000");

Suppose x=10 and y=10 what is x after evaluating the expression (y >= 10) || (x++ > 10)?

Analyze the following code fragments that assign a boolean value to the variable even.

Code 1:
if (number % 2 == 0)
even = true;
else
even = false;

Code 2:
even = (number % 2 == 0) ? true: false;

Code 3:
even = number % 2 == 0;

What is the value of the following expression?
true || true && false

Suppose x = 1, y = -1, and z = 1. What is the printout of the following statement?

if (x > 0)
if (y > 0)
System.out.println("x > 0 and y > 0");
else if (z > 0)
System.out.println("x < 0 and z > 0");

"AbA".compareToIgnoreCase("abC") returns ________.

What is the printout of System.out.println('z' - 'a')?

Assume that the ASCII code for character c is 99 and for a is 97. What is the printout of the following code?

System.out.println('a' + 'c');

Note that the Unicode for character A is 65. The expression "A" + 1 evaluates to ________.

The expression 'c' - 'e' is ________.

Math.ceil(5.5) evaluates to ________.

Math.floor(5.5) evaluates to ________.

To obtain the sine of 35 degrees, use ________.

Which of the following is the correct expression of character a?

Math.cos(Math.PI) returns ________.

What is i after the following for loop?

int y = 0;
for (int i = 0; i<10; ++i) {
y += i;
}

Which of the following will not help prevent infinite loops?

How many times will the following code print "Welcome to Java"?

int count = 0;
do {
System.out.println("Welcome to Java");
} while (++count < 10);

For the code segment below:

switch( q )
{
case 1:
System.out.println( "apple" );
break;
case 2:
System.out.println( "orange" );
break;
case 3:
System.out.println( "banana" );
break;
case 4:
System.out.println( "pear" );
case 5:
System.out.println( "grapes" );
default:
System.out.println( "kiwi" );
} // end switch

Which of the following values for q will result in kiwi being included in the output?

Which of the following for-loop control headers results in equivalent numbers of iterations:

A. for ( int q = 1; q <= 100; q++ )
B. for ( int q = 100; q >= 0; q-- )
C. for ( int q = 99; q > 0; q -= 9 )
D. for ( int q = 990; q > 0; q -= 90 )

To exit out of a loop completely, and resume the flow of control at the next line in the method, use _______.

What is the value in count after the following loop is executed?

int count = 0;
do {
System.out.println("Welcome to Java");
} while (count++ < 9);
System.out.println(count);

What is sum after the following loop terminates?

int sum = 0;
int item = 0;
do {
item++;
sum += item;
if (sum >= 4) continue;
}
while (item < 5);

What is the output for y?

int y = 0;
for (int i = 0; i<10; ++i) {
y += i;
}
System.out.println(y);

Which of the following is not a type of repetition statement in Java?

Which of the following statements about the continue statement is true?

Suppose the input for number is 9. What is the output from running the following program?

import java.util.Scanner;

public class Test {
public static void main(String[ ] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter an integer: ");
int number = input.nextInt();

int i;

boolean isPrime = true;
for (i = 2; i < number && isPrime; i++) {
if (number % i == 0) {
isPrime = false;
}
}

System.out.println("i is " + i);

if (isPrime)
System.out.println(number + " is prime");
else
System.out.println(number + " is not prime");
}
}

The parameter list in the method header and the arguments in the method call must agree in:

What is Math.rint(3.5)?

Which is a correct static method call of Math class method sqrt?

You can set a Random object's seed at any time during program execution by calling the object's ________ methods.

Identifiers in Java have ________ and ________ scopes?

A well-designed method

Which of the following methods is not in the Math class?

Which statement below could be used to simulate the outputs of rolling a six-sided die? Suppose randomNumbers is a Random object.

Which of the following can be an argument to a method?

To declare a method as static, place the keyword static before ________ in the method's declaration

Analyze the following code:

public class Test {
public static void main(String[ ] args) {
System.out.println(xMethod(5, 500L));
}

public static int xMethod(int n, long l) {
System.out.println("int, long");
return n;
}

public static long xMethod(long n, long l) {
System.out.println("long, long");
return n;
}
}

Declaring main as ________ allows the JVM to invoke main without creating an instance of the class.

Variables should be declared as fields only if

Which of the following methods are overloaded with respect to one another?

A. public int max ( int a, int b ) { … }
B. public double max ( double a, double b ) { … }
C. public int max ( int a, int b, int c ) { … }
D. public double max ( double a, double b, double c ) { … }

The identifiers in an enumeration ________.

Analyze the following code.

public class Test {
public static void main(String[ ] args) {
System.out.println(max(1, 2));
}

public static double max(int num1, double num2) {
System.out.println("max(int, double) is invoked");

if (num1 > num2)
return num1;
else
return num2;
}

public static double max(double num1, int num2) {
System.out.println("max(double, int) is invoked");

if (num1 > num2)
return num1;
else
return num2;
}
}

What is Math.floor(3.6)?

What is Math.round(3.6)?

(int)('a' + Math.random() * ('z' - 'a' + 1)) returns a random number ________.

Given the following method

static void nPrint(String message, int n) {
while (n > 0) {
System.out.print(message);
n--;
}
}

What is k after invoking nPrint("A message", k)?

int k = 2;
nPrint("A message", k);

Does the method call in the following method cause compile errors?

public static void main(String[ ] args) {
Math.pow(2, 4);
}

Method calls cannot be distinguished by ________.

________ is to implement one method in the structure chart at a time from the top to the bottom.

Which statement below could be used to simulate the outputs of tossing a quarter to get heads or tails? Suppose randomNumbers is a Random object.

A Java class can have which of the following methods?

A. void foo( int a )
B. void foo( int a, int b )
C. void foo( double a )
D. void foo( double a, double b )
E. void foo( int b )

If more method calls occur than can have their activation records stored on the program execution stack, an error known as a ________ occurs.

Which statement creates a random value from the sequence 2, 5, 8, 11 and 14. Suppose randomNumbers is a Random object.

Analyze the following code:

public class Test {
public static void main(String[ ] args) {
final int[ ] x = {1, 2, 3, 4};
int[ ] y = x;

x = new int[2];

for (int i = 0; i < y.length; i++)
System.out.print(y[i] + " ");
}
}

For the binarySearch method in Section 6.9.2, what is low and high after the first iteration of the while loop when invoking binarySearch(new int[ ]{1, 4, 6, 8, 10, 15, 20}, 11)?

Analyze the following code.

public class Test {
public static void main(String[ ] args) {
int[ ] x = new int[3];
System.out.println("x[0] is " + x[0]);
}
}

Assume int[ ] scores = {1, 20, 30, 40, 50}, what value does java.util.Arrays.binarySearch(scores, 30) return?

Analyze the following code:

public class Test {
public static void main(String[ ] args) {
int[ ] x = new int[5];
int i;
for (i = 0; i < x.length; i++)
x[i] = i;
System.out.println(x[i]);
}
}

The reverse method is defined in the textbook. What is list1 after executing the following statements?

int[ ] list1 = {1, 2, 3, 4, 5, 6};
list1 = reverse(list1);

What would be the result of attempting to compile and run the following code?

public class Test {
public static void main(String[ ] args) {
double[ ] x = new double[ ]{1, 2, 3};
System.out.println("Value is " + x[1]);
}
}

Do the following two programs produce the same result?

Program I:
public class Test {
public static void main(String[ ] args) {
int[ ] list = {1, 2, 3, 4, 5};
reverse(list);
for (int i = 0; i < list.length; i++)
System.out.print(list[i] + " ");
}

public static void reverse(int[ ] list) {
int[ ] newList = new int[list.length];

for (int i = 0; i < list.length; i++)
newList[i] = list[list.length - 1 - i];

list = newList;
}
}

Program II:
public class Test {
public static void main(String[ ] args) {
int[ ] oldList = {1, 2, 3, 4, 5};
reverse(oldList);
for (int i = 0; i < oldList.length; i++)
System.out.print(oldList[i] + " ");
}

public static void reverse(int[ ] list) {
int[ ] newList = new int[list.length];

for (int i = 0; i < list.length; i++)
newList[i] = list[list.length - 1 - i];

list = newList;
}
}

The selectionSort method is defined in this section. What is list1 after executing the following statements?

double[ ] list1 = {3.1, 3.1, 2.5, 6.4};
selectionSort(list1);

If a key is not in the list, the binarySearch method returns ________.

What is the correct term for numbers[99]?

If you declare an array double[ ] list = {3.4, 2.0, 3.5, 5.5}, list[1] is ________.

The ________ method sorts the array scores of the double[ ] type.

Assume double[ ][ ] x = new double[4][5], what are x.length and x[2].length?

Suppose a method p has the following heading:

public static int[ ][ ] p()

What return statement may be used in p()?

Assume int[ ] scores = {1, 20, 30, 40, 50}, what value does java.util.Arrays.binarySearch(scores, 3) return?

What is the representation of the third element in an array called a?

Which of the following statements are correct?

Assume double[ ][ ][ ] x = new double[4][5][6], what are x.length, x[2].length, and x[0][0].length?

Analyze the following code:

public class Test {
public static void main(String[ ] args) {
boolean[ ][ ] x = new boolean[3][ ];
x[0] = new boolean[1]; x[1] = new boolean[2];
x[2] = new boolean[3];

System.out.println("x[2][2] is " + x[2][2]);
}
}

In the following code, what is the printout for list2?

class Test {
public static void main(String[ ] args) {
int[ ] list1 = {1, 2, 3};
int[ ] list2 = {1, 2, 3};
list2 = list1;
list1[0] = 0; list1[1] = 1; list2[2] = 2;
for (int i = 0; i < list2.length; i++)
System.out.print(list2[i] + " ");
}
}

Which of the following errors is synchronous?

When an unchecked exception occurs in a method but is not caught:

What is displayed on the console when running the following program?

class Test {
public static void main(String[ ] args) {
try {
System.out.println("Welcome to Java");
int i = 0;
double y = 2.0 / i;
System.out.println("Welcome to HTML");
}
finally {
System.out.println("The finally clause is executed");
}
}
}

What exception type does the following program throw?

public class Test {
public static void main(String[ ] args) {
String s = "abc";
System.out.println(s.charAt(3));
}
}

What is displayed on the console when running the following program?

class Test {
public static void main(String[ ] args) {
try {
System.out.println("Welcome to Java");
int i = 0;
int y = 2/i;
System.out.println("Welcome to Java");
}
catch (RuntimeException ex) {
System.out.println("Welcome to Java");
}
finally {
System.out.println("End of the block");
}
}
}

What is displayed on the console when running the following program?

class Test {
public static void main(String[ ] args) {
try {
method();
System.out.println("After the method call");
}
catch (RuntimeException ex) {
System.out.println("RuntimeException");
}
catch (Exception ex) {
System.out.println("Exception");
}
}

static void method() throws Exception {
try {
String s = "5.6";
Integer.parseInt(s); // Cause a NumberFormatException

int i = 0;
int y = 2 / i;
System.out.println("Welcome to Java");
}
catch (NumberFormatException ex) {
System.out.println("NumberFormatException");
throw ex;
}
catch (RuntimeException ex) {
System.out.println("RuntimeException");
}
}
}

Which of the following statements is false?

Analyze the following code:

class Test {
public static void main(String[ ] args) {
try {
int zero = 0;
int y = 2/zero;
try {
String s = "5.6";
Integer.parseInt(s); // Cause a NumberFormatException
}
catch(Exception e) {
}
}
catch(RuntimeException e) {
System.out.println(e);
}
}
}

To catch an exception, the code that might throw the exception must be enclosed in a

An uncaught exception:

What exception type does the following program throw?

public class Test {
public static void main(String[ ] args) {
int[ ] list = new int[5];
System.out.println(list[5]);
}
}

After a finally block has finished executing (and there are no exceptions to be handled):

What is displayed on the console when running the following program?

class Test {
public static void main(String[ ] args) {
try {
System.out.println("Welcome to Java");
int i = 0;
int y = 2/i;
System.out.println("Welcome to Java");
}
finally {
System.out.println("End of the block");
}

System.out.println("End of the block");
}
}

Which of the following is not included in an exception's stack trace?

Which of the following statements is false?

Attributes of a class are also known as:

________ is invoked to create an object.

What type of methods allow a client of a class to assign values to a private instance variable?

What is the value of myCount.count displayed?

public class Test {
public static void main(String[ ] args) {
Count myCount = new Count();
int times = 0;

for (int i=0; i<100; i++)
increment(myCount, times);

System.out.println(
"myCount.count = " + myCount.count);
System.out.println("times = "+ times);
}

public static void increment(Count c, int times) {
c.count++;
times++;
}
}

class Count {
int count;

Count(int c) {
count = c;
}

Count() {
count = 1;
}
}

Suppose you wish to provide an accessor method for a boolean property finished, what signature of the method should be?

What is the printout of the third println statement in the main method?

public class Foo {
int i;
static int s;

public static void main(String[ ] args) {
Foo f1 = new Foo();
System.out.println("f1.i is " + f1.i + " f1.s is " + f1.s);
Foo f2 = new Foo();
System.out.println("f2.i is " + f2.i + " f2.s is " + f2.s);
Foo f3 = new Foo();
System.out.println("f3.i is " + f3.i + " f3.s is " + f3.s);
}

public Foo() {
i++;
s++;
}
}

Sending a message to an object means that:

Analyze the following code and choose the best answer:

public class Foo {
private int x;

public static void main(String[ ] args) {
Foo foo = new Foo();
System.out.println(foo.x);
}
}

Analyze the following code:

public class Test {
public static void main(String[ ] args) {
double radius;
final double PI= 3.15169;
double area = radius * radius * PI;
System.out.println("Area is " + area);
}
}

Analyze the following code:

public class Test {
private int t;

public static void main(String[ ] args) {
int x;
System.out.println(t);
}
}

Analyze the following code:

public class Test {
public static void main(String args[ ]) {
NClass nc = new NClass();
nc.t = nc.t++;
}
}

class NClass {
int t;
private NClass() {
}
}

A method that is associated with an individual object is called ________.

When invoking a method with an object argument, ________ is passed.

What is the printout for the first statement in the main method?

public class Foo {
static int i = 0;
static int j = 0;

public static void main(String[ ] args) {
int i = 2;
int k = 3;
{
int j = 3;
System.out.println("i + j is " + i + j);
}

k = i + j;
System.out.println("k is " + k);
System.out.println("j is " + j);
}
}

In the UML, a class's attributes are placed in the ________ compartment of the class's rectangle.

You can declare two variables with the same name in ________.

We can derive many of the operations of each class by examining the key ________ and ________ in the requirements documents.