Java Ch 8 - 11

¡Supera tus tareas y exámenes ahora con Quizwiz!

SavingsAccount.getNumberOfAccounts();

If you have defined a class SavingsAccount with a public static method getNumberOfAccounts(), and created a SavingsAccount object referenced by the variable account20, which of the following will call the getNumberOfAccounts()method?

double x = Double.parseDouble(str);

To convert the string, str = "285.74" to a double and store it in the variable x, use the following statement.

Write a copy method that will make a field by field copy of the two objects

To copy an object to another object of the same class

ABC

What will be printed after the after the following code is executed? String str = "abc456"; int i = 0; while (1<6) { if(character.isLetter(str.charAt(i)) System.out.println(Character.toUpperCase(charAt(i))); i++; }

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

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

123, 456 7890, and -

What will be the tokens in the following statement? StringTokenizer = strToken new StringTokenizer("123-456-7890", "-",true);

15

What will be the value of loc after the following code is executed? int loc; String str = "The cow jumped over the moon." loc = str.indexOf("ov");

True

What will be the value of matches after the following code is executed? boolean matches; String[] productCodes = {"456HI345", "3456hj"}; matches = productCodes[0].regionMatches(true, 1, productCode[1], 2, 3)

We have lived in Tampa, Trenton, and Atlanta.

What will be the value of strbuff after the following statements are executed? StringBuffer strbuff = new StringBuffer('We have lived in Chicago, Trenton, and Atlanta." strbuff.replace(17,24,"Tampa");

180

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 = 100; for(int i = 0; i < SUB; i++) { x[i] = y; y += 10; }

a case expression

You cannot use the fully-qualifed name of an enum constant for this

A case experssion

You cannot use the fully-qualified name of an enum constant for this

numAccounts = SavingsAccount.numberOfAccounts;

If you have defined a class named SavingsAccountwith a public static data member namednumberOfAccounts, and created a SavingsAccountobject referenced by the variable account20, which of the following will assign numberOfAccounts to numAccounts?

1

Look at the Following declaration: enum Tree { OAK, MAPLE, PINE } What is the ordinal value of the MAPLE enum constant?

Tree.PINE

Look at the following declaration. enum Tree { OAK, MAPLE, PINE } What is the fully-qualified name of the PINE enum constant?

Give the object, str, 25 bytes of storage and not store anything in them

The following StringBuffer constructor will StringBuffer str = new String Buffer(25)

**It specifies that only String objects may be stored in the ArrayList object.

The following statement creates an ArrayListobject. What is the purpose of the notation? ArrayList<String> arr = new ArrayList<String>();

String str = Double.toString(d);

To convert the double variable, d = 543.98, to a string, use the following statement,

integer x = Integer.parseInt(str);

To convert the string, str = "285" to an integer and store it in the variable x, use the following statement

It creates a Float Object; It initializes that object to 8.8; It assigns the object's address to the number variable

What does the following statement do? Float number = new Float(8.8);

False

What eill be the value of matches after the following code has been executed> boolean matches; String str1 = "The cow jumped over the moon."; String str2 = "moon'; matches = str1.endsWith(str2);

The address of an object in the class Rectangle

What will be returned from a method, if the following is the method header: public Rectangle getRectangle()

60

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; }

. It must be the first statement in the constructor making the call

When the this variable is used to call a constructor,

trim

When you are writing with string objects that may have unwanted spaces at the beginning or end of the strings, use the ____ method to delete them.

The equals and compareTo methods that automatically come with the enum data type

You may use this to compare two enum data values.

False

You must call a method to get the value of a wrapper class object

True

A class's static methods do not operate on the fields that belong to any instance of the class

Only Public and protected members of the base class

A derived class can directly access

Methods of the same class; Methods of a Subclass; Methods in the Same Package

A protected member of a class may be directly accessed by

Are final and static

All fields declared in an interface

False

All methods in an abstract class must also be declared abstract

They provide static methods that are very useful

Although it is not normally useful to create objects from the wrapper classes, programmers might use wrapper classes because

True

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

True

An abstract class is not instantiated, but serves as a superclass for other classes.

True

An instance of a class does not have to exist in order for values to be stored in a class's static fields

remove

This ArrayList class method deletes an item from an ArrayList.

All of the above

What does the following statement do? double[] array1 = new double[10];

456

What will be printed after the after the following code is executed? String str = "abc456"; int i = 0; while (1<6) { if(!Character.isLetter(str.charAt(i)) System.out.println(Character.toUpperCase(charAt(i))); i++; }

We have lived in Chicago, Tampa, and Atlanta.

What will be the value of strbuff after the following statements are executed? StringBuffer strbuff = new StringBuffer('We have lived in Chicago, Trenton, and Atlanta." strbuff.replace(26,33,"Tampa");

38

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; } }

x[] = {36, 78, 12, 24} and y[] = {36, 78, 12, 24}

What would be the results after the following code was executed? int[] x = {23, 55, 83, 19}; int[] y = {36, 78, 12, 24}; x = y; y = x;

Value contains the lowest value in array1

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]; }

A reference to an object of that class

When a method's return type is a class, what is actually returned to the calling program?

All the characteristics of the general object, plus additional chracteristics

When an "is a" relationship exists between objects, it means that the specialized object has

True

When an Object is passed to a method, the method may change the values in the object

False

When an interface variable references an object you can use the interface variable to call all the methods in the class implementing the interface.

Private Members

When declaring class data members, it is best to declare them as

System.out.println(Integer.MAX_VALUE);

Which of the following Statements will print the maximum value an integer variable may have?

They are called from an instance of the class.

Which of the following is not true about static methods?

False

You can declare an enumerated data type inside of a method.

add

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

set

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

False

You cannot assign a value to a wrapper class object.

The array numbers has 6 rows and 9 columns

Given the following two-dimensional array declaration, which statement is true? int [][] numbers = new int [6] [9];

Public members in ClassB are public in ClassA, but private members in ClassB cannot be directly accessed in ClassA

If ClassA is Derived from ClassB, then

A chain of inheritance

If ClassC is derived from ClassB, which is derived from ClassA, this would be an example of

The method will have only a header, but not a body, and end with a semicolon

If a class contains an abstract method,

False

If a method in a subclass has the same signature as a method in the superclass, the subclass method overloads the superclass method.

False

If a string has more than one character used as a delimiter, we must write a loop to determine the tokens, one fore each delimiter character.

This is a public method that accepts a FeetInches object as its argument and returns a boolean value

If the following is from the method section of a UML diagram, which of the following statements is true? + equals(object2:Stock) : boolean

A compiler error will result if it is not the first statement of the constructor

If the this variable is used as a constructor call,

False

If two methods in the same class have the same name but different signatures, the second overrides the first.

True

If you are using characters other than whitespaces as delimeters, you will probably want to trim the string before tokenizing; otherwise, the leading and/or following whitespaces will become part of the first and/or last token

Package

If you do not provide an access specifier for a class member, the class member is given ___ access by default

Semicolon

If you do not specify delimiters in the StringToken constructor, which of the following cannot be a delimiter?

The more general classes are toward the top of the tree and the more specialized are toward the bottom

In a class hierachy

Token

In a string that contains a series of words or other items of data separated by spaces or other characters, the programming term for the data items is

False

In an inheritance relationship, the derived class constructor always executes before the base class constructor

Public access

In an interface all methods have

Consists of an array of references to Stringobjects

In memory, an array of String objects

True

It is not possible for a super class to call a subclass's method.

#

Protected class members are denoted in a UML diagram with the symbol

True

StringBuffer objects are not immutable.

garbage collection

The JVM periodically performs this process to remove unreferenced objects from memory.

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

The binary search algorithm

Protected members may be accessed by methods in the same package or in a derived class, even when the derived class is in a different package

The difference between protected access and package is

They cannot refer to non-static members of the class

The only limitation that static methods have is

16 characters

The parameterless constructor for a StringBuffer object gives the object enough storage space to hold ___

System.out println(Double.MAX_VALUE);

which of the following statements will print the maximum value a double variable may have?

ordinal

Enumerated types have this method, which returns the position of an enum constant in the declaration list.

True

Every class has a toString method and equal's method inherited from the Object class

True

Every class is either directly or indirectly derived from he Object class.

public class Salaried extends PayType

Which of the following statements declares as a subclass of PayType?

char[ ]

In the following statement, what data type must recField be: str.getChars(5, 10, recField, 0);

True

If you write a toString method for a class, Java will automatically call the method any time you concatenate an object of the class with a string.

With a line that has an open arrowhead at one end that point to the base class

In UML diagrams, inheritance is shown

The array must first be sorted in ascending order

In order to do a binary search on an array,

Not quite private; Not quite different

Protected members are

False

StringBuffer objects are immutable.

Testing and converting char variables

The Character wrapper provides numerous methods for

True

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

Write an equals method that will make a field by field comparison of the two object

To compare two objects

String str = Integer.toString(number);

To convert the integer vaiable, number = 56, to a string, use the following statement

import java.util.StringTokenizer;

To use the class StringTokenizer, you must have the following import statement.

Use the concat() method or use the + between the two Strings

Two ways of concatenating two strings are

No import statement is needed

Use the following import statement when using the character wrapper class

diddl

What is the value of str after the followuing code has been executed? String str; Strinf sourceStr = 'Hey diddle, diddle, the cat and the fiddle"; str = sourceStr.substring(12,17);

It Creates a Double Object; It initializes that object to 8.8; It assigns the object's address to the number variable

What does the following statement do? Double number = new Double(8.8);

"is a"

When on object is a specialized version of another object, there is a(n) ____ relationship between them.

Another StringBuffer type

When using StringBuffer insert method, you cannot insert

-1

What will be the value of loc after the following code is executed? int loc; String str = "The cow jumped over the moon." loc = str.lastIndexOf("ov",14);

public class ClassA implements Interface1, Interface2, Interface3

Which of the following statements correctly specifies three interfaces:

January, 1, 2004, space, comma

what will be the tokens in the following statements? StringTokenizer strToken = newStringTokenizer("January 1, 2003", ",",true);

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.

33

int[] x = {22, 33, 44}; arrayProcess(x[1]); ... public static void arrayProcess(int a) { a = a + 5; }

A two-dimensional array when the rows are of different lengths

A ragged array is

They are immutable, They are not easy to use

Few programmers use wrapper classes because

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

The sequential search algorithm

Has a

The term for the relationship created by object aggregation is

False

The valueOf() method accepts a string representation as an argument and returns its equivalent integer value.

True

The valueOf() method accepts a value of any primitive data type as an argument and returns a string representation of the value.

A compiler error will result, if it is not the first statement of the constructor

If the this variable is used as a constructor call,

9

For the following code, how many times would the loop execute? StringTokenizer strToken = new StringTokenizer("Cars, trucks, and SUVs are all types of automobiles."); while(strToken.hasMoreTokens) { System.out.println(strToken.nextToken()); }

7

For the following code, how many times would the while loop execute? StringTokenizer strToken = new StringTokenizer('Ben and Jerry's ice cream is great.'); while (strToken.hasMoreTokens) { System.out.println(strToken.nextToken()); }

A reference to the String "ghi"

For the following code, what would be the value of str[2]? String[] str = {"abc", "def", "ghi", "jkl"};

str[0].toUpperCase();

Given that String[] str has been initialized, to get a copy of str[0] with all characters converted to upper case, use the following statement

ClassB must override each method in ClassA

Given the following statement which of the following is true? public class ClassB implements ClassA{ }

The insert will start at position 32

Given the following statement, which of the following is not true? str.insert(8,32)

f

If String str = "ABCDEFGHI," what will be returned from Character.toLowerCase(str.charAt(5))?

W

If String str = "RSTUVWXYZ", what will be the value returned from str.charAt(5)?

Then a class that is derived from it, must call one of the constructors that the base class does have

If a base class does not have a default constructor,

You cannot create an instance of the class; The method will have only a header, but not a body, and end with a semicolon; Then Method must be overridden in subclasses

If a class contains an abstract method

True

If a non-letter is passed to toLowerCase or toUpperCase method, it is returned unchanged

Java will automatically call the superclass's default constructor just before the code in the subclass's constructor executes

If a subclass constructor does not explicitly call as superclass constructor,

False

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

for (int row = 0; row < numbers.length; row++) { for (int col = 0; col < numbers[row].length; col++) total += numbers[row][col]; }

If numbers is a two-dimensional int array that has been initialized and total is an int that has been set to 0, which of the following will sum all the elements in the array?

True

If you write a toString method to display the contents of an object, object1, for a class, Class1, then the following two statements are equivalent: System.out.println(object1); System.out.println(object1.toString());

With a line that has an open arrowhead at one end that points to the superclass

In UML diagrams, inheritance is shown

Delimiter

In a string that contains a series of words or other items of data separated by spaces or other characters, the programming term for the spaces or other characters is

ClassB

In the following statement which is the base class? public class ClassA extends ClassB implements ClassC

True

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

x[] = {36, 78, 12, 24} and y[] = {36, 78, 12, 24}

What would be the results after the following code was executed? int[] x = {23, 55, 83, 19}; int[] y = {36, 78, 12, 24}; for(int a = 0; a < x.length; a++) { x[a] = y[a]; y[a] = x[a]; }

str would equal " Little Jack Horner sat on the corner"

What would be the results of executing the following code? StringBuffer str = new String Bufffer("Little Jack Horner") str.append("sat on the"); str.append("corner");

strbuff would equal "The cow jumped over the moon"

What would be the results of executing the following code? StringBuffer strbuff = new StringBuffer(12); strbuff.append("The cow"); strbuff.append("jumped over the"); strbuff.append("moon");

value contains the sum of all the values in array1

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]; }

a = 5

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;


Conjuntos de estudio relacionados

ACCOUNTING FOR MERCHANDISING BUSINESS (TERMS)

View Set

Cells: The Living Units Dynamic Study Module

View Set