Cisc 115 intro to java final exam

Réussis tes devoirs et examens dès maintenant avec Quizwiz!

In a @return tag statement the description:

describes the return value

Given the following statement, which statement will write "Calvin" to the file DiskFile.txt? PrintWriter diskOut = new PrintWriter("DiskFile.txt");

diskOut.println("Calvin");

This type of loop is ideal in situations where you always want the loop to iterate at least once

do-while loop

Variables of the boolean data type are useful for:

evaluating true/false conditions

A Java program will not compile unless it contains the correct line numbers.

false

All Java statements end with semicolons.

false

An important style rule you should follow when writing if statements is to line up the conditionally executed statement with the if statement

false

Assuming that pay has been declared a double, the following statement is valid. pay = 2,583.44;

false

Because the || operator performs short-circuit evaluation, your boolean expression will generally be evaluated faster if the subexpression that is most likely to be true is on the left.

false

Class names and key words are examples of variables.

false

Colons are used to indicate the end of a Java statement.

false

In Java the variable named total is the same as the variable named Total.

false

In a for statement, the control variable can only be incremented

false

In the for loop, the control variable cannot be initialized to a constant value and tested against a constant value.

false

In the method header the static method modifier means the method is available to code outside the class. True

false

In the method header, the method modifier public means that the method belongs to the class, not a specific object.

false

Java is a case-insensitive language.

false

Java source files end with the .class extension.

false

Only constants and variables may be passed as arguments to methods.

false

Programs never need more than one path of execution.

false

The do-while loop is a pre-test loop.

false

When testing for character values, the switch statement does not test for the case of the character.

false

When the break statement is encountered in a loop, all the statements in the body of the loop that appear after it are ignored, and the loop prepares for the next iteration.

false

When two Strings are compared using the compareTo method, the cases of the two strings are not considered.

false

Which of the following is valid?

float w; w = 1.0f;

This type of loop is ideal in situations where the exact number of iterations is known.

for loop

________ refers to the physical components that a computer is made of.

hardware

The ________ statement is used to make simple decisions in Java.

if

Which of the following correctly tests the char variable chr to determine whether it is NOT equal to the character B?

if (chr != 'B')

If chr is a character variable, which of the following if statements is written correctly?

if (chr == 'a')

When using the PrintWriter class, which of the following import statements would you write near the top of your program?

import java.io.*;

If a loop does not contain within itself a way to terminate, it is called a(n):

infinite loop

In Java, you do not use the new operator when you use a(n):

initialization list

Which of the following is a valid declaration for a ragged array?

int[][] ragged = new int[5][];

A sentinel value ________ and signals that there are no more values to be entered.

is a special value that cannot be mistaken as a member of the list

A search algorithm:

is a way to locate a specific item in a larger collection of data

When an argument is passed to a method:

its value is copied into the method's parameter variable

The ArrayList class is in this package.

java.util

Which of the following will compile a program called ReadIt?

javac ReadIt.java

You should always document a method by writing comments that appear:

just before the method's definition

Each array in Java has a public field named ________ that contains the number of elements in the array.

length

To return an array of long values from a method, use this as the return type for the method.

long[]

This part of a method is a collection of statements that are performed when the method is executed.

method body

Which Scanner class method reads an int?

nextInt()

Which of the following values can be passed to a method that has an int parameter variable? float double long all of these none of these

none of these

You use this method to determine the number of items stored in an ArrayList object.

numberItems

In the following code, what values could be read into number to terminate the while loop? Scanner keyboard = new Scanner(System.in); System.out.print("Enter a number "); int number = keyboard.nextInt(); while (number < 100 || number > 500) { System.out.print("Enter another number: "); number = keyboard.nextInt(); }

numbers in the range 100-500

If numbers is a two-dimensional array, which of the following would give the length of row r?

numbers[r].length

The lifetime of a method's local variable is

only while the method is executing

Which of the following is included in a method call?

parentheses

In the header, the method name is always followed by this:

parenthesis

This type of loop will always be executed at least once.

post-test loop

Which of the following is a correct method header for receiving a two-dimensional array as an argument?

public static void passArray(int[2]) B) public static void passArray(int [][])

This ArrayList class method deletes an item from an ArrayList.

remove

Which of the following is NOT part of a method call?

return type

This is a sum of numbers that accumulates with each iteration of a loop

running total

Which of the following is NOT a part of the method header?

semicolon

This is a value that signals when the end of a list of values has been reached.

sentinel

You can use this ArrayList class method to replace an item at a specific location in an ArrayList.

set

Which of the following would be a valid method call for the following method? public static void showProduct (int num1, double num2) { int product; product = num1 * (int)num2; System.out.println("The product is " + product); }

showProduct(10, 4.5);

Character literals are enclosed in ________; string literals are enclosed in ________.

single quotes; double quotes

Another term for programs is:

software

What do you call the number that is used as an index to pinpoint a specific element within an array?

subscript

In order to do a binary search on an array:

the array must first be sorted in ascending order

This indicates the number of elements, or values, the array can hold.

the array's size declarator

In the following code, what values could be read into number to terminate the while loop? Scanner keyboard = new Scanner(System.in); System.out.print("Enter a number "); int number = keyboard.nextInt(); while (number < 100 && number > 500) { System.out.print("Enter another number "); number = keyboard.nextInt(); }

the boolean condition can never be true

When an individual element of an array is passed to a method:

the method does not have direct access to the original array

A parameter variable's scope is:

the method in which the parameter is declared

When you pass an argument to a method, be sure that the argument's data type is compatible with:

the parameter variable's data type

The phrase divide and conquer is sometimes used to describe:

the process of breaking a problem down into smaller pieces

In an if/else statement, if the boolean expression is false:

the statement or block following the else is executed

What will be the value of x after the following code is executed? int x = 10; while (x < 100); { x += 10; }

this is an infinite loop

A file must always be opened before using it and closed when the program is finished using it.

true

A parameter variable's scope is the method in which the parameter is declared.

true

A value-returning method can return a reference to a non-primitive type

true

A variable's scope is the part of the program that has access to the variable.

true

Although the dollar sign is a legal identifier character, you should not use it because it is normally used for special purposes.

true

An important style rule you should adopt for writing if statements is to write the conditionally executed statement on the line after the if statement.

true

Any method that calls a method with a throws clause in its header must either handle the potential exception or have the same throws clause.

true

Application software refers to programs that make the computer useful to the user.

true

Because the && operator performs short-circuit evaluation, your boolean expression will usually execute faster if the subexpression that is most likely false is on the left of the && operator.

true

Constants, variables, and the values of expressions may be passed as arguments to a method.

true

Each byte is assigned a unique number known as an address.

true

If the compiler encounters a statement that uses a variable before the variable is declared, an error will result.

true

Java provides a set of simple unary operators designed just for incrementing and decrementing variables.

true

Methods are commonly used to break a problem into small manageable pieces.

true

Named constants are initialized with a value, that value cannot be changed during the execution of the program.

true

No statement outside the method in which a parameter variable is declared can access the parameter by its name.

true

Programming style includes techniques for consistently putting spaces and indentation in a program so visual cues are created.

true

The Java Virtual Machine is a program that reads Java byte code instructions and executes them as they are read

true

The computer is a tool used by so many professions that it cannot be easily categorized

true

The do-while loop must be terminated with a semicolon.

true

The expression in a return statement can be any expression that has a value.

true

The if/else statement will execute one group of statements if its boolean expression is true or another group if its boolean expression is false

true

The while loop has two important parts: (1) a boolean expression that is tested for a true or false value, and (2) a statement or block of statements that is repeated as long as the expression is true.

true

Two general categories of methods are void methods and value returning methods

true

When testing for character values, the switch statement does not test for the case of the character.

true

When the continue statement is encountered in a loop, all the statements in the body of the loop that appear after it are ignored, and the loop prepares for the next iteration.

true

When you open a file with the PrintWriter class, the class can potentially throw an IOException.

true

When you pass the name of a file to the PrintWriter constructor, and the file already exists, it will be erased and a new empty file with the same name will be created.

true

Without programmers, the users of computers would have no software, and without software, computers would not be able to do anything.

true

You can use the PrintWriter class to open a file for writing and write data to it.

true

You must have a return statement in a value-returning method.

true

A Boolean expression is one that is either:

true or false

The expression tested by an if statement must evaluate to:

true or false

A flag may have the values:

ture or false

This type of loop allows the user to decide the number of iterations

user controlled loop

The sequential search algorithm

uses a loop to sequentially step through an array, starting with the first element

This type of method performs a task and sends a value back to the code that called it.

value-returning

In Java, ________ must be declared before they can be used

variables

This type of method performs a task and then terminates.

void

Assume that inputFile references a Scanner object that was used to open a file. Which of the following while loops shows the correct way to read data from the file until the end of the file is reached?

while (inputFile.hasNext()) { ... }

Which of the following are pre-test loops?

while, for

The binary search algorithm:

will cut the portion of the array being searched in half each time the loop fails to locate the search value

What will be the values of x and y as a result of the following code? int x = 25, y = 8; x += y++;

x = 33, y = 9

What will be printed when the following code is executed? int y = 10; if ( y == 10) { int x = 30; x += y; } System.out.print("x = "); System.out.print(x);

x is unknown when the last statement is executed

Which of the following expressions will determine whether x is less than or equal to y?

x<=y

Which one of the following is the not equal operator?

!=

Which of the following is NOT a valid comment statement?

*/ comment 3 /*

The increment operator is:

++

Subscript numbering always starts at what value?

0

If final int SIZE = 15 and int[] x = new int[SIZE], what would be the range of subscript values that could be used with x[]?

0 through 14

How many times will the following do-while loop be executed? int x = 11; do { x += 20; } while (x > 100);

1

What will be the value of x after the following code is executed? int x = 10; while (x < 100) { x += 10; }

100

int bonus, sales = 10000; if (sales < 5000) bonus = 200; else if (sales < 7500) bonus = 500; else if (sales < 10000) bonus = 750; else if (sales < 20000) bonus = 1000; else bonus = 1250;

1000

How many times will the following for loop be executed? for (int count = 10; count <= 21; count++) System.out.println("Java is great!!!");

11

What does the following code display? double x = 12.3798146; System.out.printf("%.2f\n", x);

12.38

What is the value of x after the following code has been executed? int x = 75; int y = 90; if ( x != y) x += y;

165

What will be returned from the following method? public static double methodA() { double a = 8.5 + 9.5; return a; }

18.0

If str1 and str2 are both Strings, which of the following expressions will correctly determine whether they are equal? (1)(str1 == str2) (2) str1.equals(str2) (3)(str1.compareTo(str2) == 0)

2 and 3

What would be the value of bonus after the following statements are executed? int bonus, sales = 1250; if (sales > 1000) bonus = 100; if (sales > 750) bonus = 50; if (sales > 500) bonus = 25; else bonus = 0;

25

What will be the value of x after the following code is executed?

28

If str1 and str2 are both Strings, which of the following will correctly test to determine whether str1 is less than str2? (1) (str1 < str2) (2) (str1.equals(str2) < 0) (3) (str1.compareTo(str2) < 0)

3

What will be the value of x[1] after the following code is executed? int[] x = {22, 33, 44}; arrayProcess(x); ... public static void arrayProcess(int[] a) { for(int k = 0; k < 3; k++) { a[k] = a[k] + 5; } }

38

What will be the value of x after the following code is executed? int x = 10; for (int y = 5; y < 20; y +=5) x += y;

40

int x = 11; do { x += 20; } while (x <= 100);

5

What will be printed after the following code is executed? for (int number = 5; number <= 15; number +=3) System.out.print(number + ", ");

5,8,11,14

What will be the value of x[8] after the following code has been executed? final int SUB = 12; int[] x = new int[SUB]; int y = 20; for(int i = 0; i < SUB; i++) { x[i] = y; y += 5; }

60

17 % 3 * 2 - 12 + 15

7

A byte is a collection of:

8 bits

When writing the documentation comments for a method, you can provide a description of each parameter by using a:

@param tag

To do a case insensitive compare which of the following could be used to test the equality of two strings, str1 and str2?

A and B

Which of the following is not part of the programming process?

All of the above (Design, Testing, Debugging)

Which of the following is a secondary storage device?

All of the above (Hard drives, floppy disks, USB drives)

The major components of a typical computer system consist of:

All of these

What do you normally use with a partially-filled array?

An accompanying integer value that holds the number of items stored in the array

What will be the result of executing the following code? int[] x = {0, 1, 2, 3, 4, 5};

An array of 6 values ranging from 0 through 5 and referenced by the variable x will be created.

What will be returned from the following method? public static float[] getValue(int x)

An array of float values

What will be the results of the following code? final int ARRAY_SIZE = 5; float[] x = float[ARRAY_SIZE]; for(int i = 1; i <= ARRAY_SIZE; i++) { x[i] = 10.0; }

An error will occur when the program runs.

Each repetition of a loop is known as what?

An iteration

These operators use two operands:

Binary

Computer programming is: An art A science Both of the above neither of the above

Both of the above

An operating system can be categorized according to:

Both the number of users that can be accommodated, and the number of tasks they can perform at one time

If you are using a block of statements, don't forget to enclose all of the statements in a set of:

Braces

Any method that calls a method with a throws clause in its header must: A. handle the potential exception B. have the same throws clause C. both A and B D. do nothing, the called program will take care of the throws clause

C. Both A and B

In the programming process which of the following is NOT involved in defining what the program is to do:

Compile code

If method A calls method B, and method B calls method C, and method C calls method D, when method D finishes, what happens?

Control is returned to method C.

A loop that repeats a specific number of times is known as a(n):

Counter controlled loop

Local variables: A. are hidden from other methods B. may have the same name as local variables in other methods C. lose the values stored in them between calls to the method in which the variable is declared D. All of these

D. All of these

results in only the object's methods being able to directly access and make the changes to the object's data.

Data hiding

Which one of the following would contain the translated Java byte code for a program named Demo?

Demo.class

What is wrong with the following method call? displayValue (double x);

Do not include the data type in the method call.

Which one of the following methods would you use to convert a string to a double?

Double.ParseDouble

A sorting algorithm is used to locate a specific item in a larger collection of data.

False

An array can hold multiple values of several different data types simultaneously

False

If a[] and b[] are two integer arrays, the expression a == b compares the array contents.

False

In a switch statement, if two different values for the CaseExpression would result in the same code being executed, you must have two copies of the code, one after each CaseExpression.

False

Java limits the number of dimensions that an array may have to 15.

False

Which of the following will open a file named MyFile.txt and allow you to append data to its existing contents?

FileWriter fwriter = new FileWriter("MyFile.txt", true); PrintWriter outFile = new PrintWriter(fwriter);

It is common practice to use a ________ variable as a size declarator.

Final

This is a boolean variable that signals when some condition exists in the program:

Flag

What will be displayed as a result of executing the following code? int x = 8; String msg = "I am enjoying java."; String msg1 = msg.toUpperCase(); String msg2 = msg.toLowerCase(); char ltr = msg.charAt(x); int strSize = msg.length(); System.out.println(msg); System.out.println(msg1); System.out.println(msg2); System.out.println("Character at index x = " + ltr); System.out.println("msg has " + strSize + " characters.");

I am enjoying java. I AM ENJOYING JAVA. i am enjoying java. Character at index x = o msg has 19 characters.

Which of the following is NOT a rule that must be followed when naming identifiers?

Identifiers can contain spaces.

________ is the process of inspecting data given to the program by the user and determining if it is valid

Input validation

The computer can do such a wide variety of tasks because:

It can be programmed

This is a control structure that causes a statement or group of statements to repeat.

Loop

This variable controls the number of times that the loop iterates.

Loop control variable

Suppose you are at an operating system command line, and you are going to use the following command to compile a program: javac MyClass.java Before entering the command, you must:

Make sure you are in the same directory or folder where MyClass.java is located

The switch statement is a:

Multiple alternative decision structure

What will be displayed after the following statements have been executed? final double x; x = 54.3; System.out.println("x = " + x );

Nothing, this is an error.

The original name for Java was:

Oak

A special variable that holds a value being passed into a method is called what?

Parameter

One of the design tools used by programmers when creating a model of the program is:

Pseudocode

When a computer is running a program, the CPU is engaged in a process formally known as:

The fetch/decode/execute cycle

What would be the results of the following code? final int SIZE = 25; int[] array1 = new int[SIZE]; ... // Code that will put values in array1 int value = 0; for (int a = 0; a <= array1.length; a++) { value += array1[a]; }

This would cause the program to crash.

The purpose of validating the results of the program is:

To determine whether the program solves the original problem

A sorting algorithm is a technique for scanning through an array and rearranging its contents in some specific order.

True

An ArrayList object automatically expands in size to accommodate the items stored in it.

True

Any items typed on the command-line, separated by space, after the name of the class are considered to be one or more arguments that are to be passed into the main method.

True

Declaring an array reference variable does not create an array.

True

In a switch statement, each of the case values must be unique.

True

Java does not limit the number of dimensions that an array may have.

True

Objects in an array are accessed with subscripts, just like any other data type in an array.

True

The String.format method works exactly like the System.out.printf method, except that it does not display the formatted string on the screen.

True

The String[] args parameter in the main method header allows the program to receive arguments from the operating system command-line.

True

The System.out.printf method formats a string and displays it in the console window.

True

To compare the contents of two arrays, you must compare the elements of the two arrays.

True

Unicode is an international encoding system that is extensive enough to represent ALL the characters of ALL the world's alphabets.

True

When an array of objects is declared, but not initialized, the array values are set to null.

True

This is an international coding system that is extensive enough to represent all the characters of all the world's alphabets:

Unicode

In Java, when a character is stored in memory, it is actually stored as a(n):

Unicode number

What would be the results of the following code? int[] array1 = new int[25]; ... // Code that will put values in array1 int value = array1[0]; for (int a = 1; a < array1.length; a++) { if (array1[a] < value) value = array1[a]; }

Value contains the lowest value in array1.

If you prematurely terminate an if statement with a semicolon, the compiler will: not display and error message assume you are placing a null statement there both of these

both of these

A block of code is enclosed in a set of:

braces { }

Methods are commonly used to:

break a problem down into small manageable pieces

A loop that executes as long as a particular condition exists is called a(n):

conditional loop

In memory, an array of String objects:

consists of elements, each of which is a reference to a String object

Variables are classified according to their:

data type

To create a method you must write its:

definition

This is an item that separates other items.

delimiter

Byte code instructions are:

Read and interpreted by the JVM

This type of operator determines whether a specific relationship exists between two values:

Relational

Syntax is:

Rules that must be followed when writing a program

These are used to indicate the end of a Java statement.

Semicolons

Before entering a loop to compute a running total, the program should first do this.

Set the accumulator where the total will be kept to an initial value, usually zero

________ works like this: If the expression on the left side of the && operator is false, the expression the right side will not be checked.

Short-circuit evaluation

Software refers to

Software refers to

Which of the following is NOT a primitive data type?

String

When the + operator is used with strings, it is known as the:

String concatenation operator

Java was developed by:

Sun Microsystems

Variables are:

Symbolic names made up by the programmer that represents locations in the computer's RAM

Which of the following will format 12.7801 to display as $12.78?

System.out.printf("$%,.2f", 12.7801);

Which of the following will format 12.78 to display as 12.8%?

System.out.printf("%.1f%%", 12.78);

To print "Hello, world" on the monitor, use the following Java statement:

System.out.println("Hello, world");

You can use this method to determine whether a file exists.

The File class's exists method

A program is a sequence of instructions stored in:

The computer's memory

Internally, the central processing unit (CPU) consists of two parts:

The control unit and the arithmetic and logic unit (ALU)

The header of a value-returning method must specify this.

The data type of the return value

Enclosing a group of statements inside a set of braces creates a:

block of statements

When a method tests an argument and returns a true or false value, it should return:

a boolean value

In a general sense, a method is:

a collection of statements that performs a specific task

A ragged array is:

a two-dimensional array where the rows are of different lengths

In the following code, System.out.println(num) is an example of: double num = 5.4; System.out.println(num); num = 0.0;

a void method

In all but rare cases, loops must contain within themselves

a way to terminate

What would be the results of the following code? int[] x = { 55, 33, 88, 22, 99, 11, 44, 66, 77 }; int a = 10; if(x[2] > x[5]) a = 5; else a = 8;

a=5

When an object, such as a String, is passed as an argument, it is:

actually a reference to the object that is passed

This ArrayList class method is used to insert an item into an ArrayList.

add

A for loop normally performs which of these steps?

all of these

Breaking a program down into small manageable methods: makes problems more easily solved allows for code reuse simplifies programs all of these

all of these

When an array is passed to a method: a reference to the array is passed it is passed just as an object the method has direct access to the original array all of these

all of these

Which of the following is NOT a benefit derived from using methods in programming?

all of these

A value-returning method must specify this as its return type in the method header.

an int

What will be the values of ans, x, and y after the following statements are executed? int ans = 0, x = 15, y =25; if ( x >= y) { ans = x + 10; x -=y; } else { ans = y + 10; y += x; }

ans = 35, x = 15, y = 40

What will be the values of ans, x, and y after the following statements are executed? int ans = 35, x = 50, y =50; if ( x >= y) { ans = x + 10; x -=y; } else { ans = y + 10; y += x; }

ans = 60, x =0, y =50

All @param tags in a method's documentation comment must:

appear after the general description of the method

Values that are sent into a method are called:

arguments


Ensembles d'études connexes

Introduction to Business Communication

View Set

Chapter 12: Gene Expression At The Molecular Level I: Production of mRNA and Proteins

View Set

Algebra 1-2 Semester 2 Final page 1

View Set

anatomy chapter 9 sensory system quiz

View Set