question

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

answer

True

question

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

answer

A case experssion

question

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

answer

1

question

If the this variable is used as a constructor call,

answer

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

question

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

answer

True

question

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?

answer

SavingsAccount.getNumberOfAccounts();

question

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

answer

garbage collection

question

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

answer

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

question

You may use this to compare two enum data values.

answer

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

question

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

answer

Tree.PINE

question

If the this variable is used as a constructor call,

answer

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

question

To copy an object to another object of the same class

answer

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

question

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

answer

ordinal

question

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?

answer

numAccounts = SavingsAccount.numberOfAccounts;

question

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

answer

A reference to an object of that class

question

The only limitation that static methods have is

answer

They cannot refer to non-static members of the class

question

When the this variable is used to call a constructor,

answer

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

question

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

answer

False

question

The term for the relationship created by object aggregation is

answer

Has a

question

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());

answer

True

question

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

answer

a case expression

question

To compare two objects

answer

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

question

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

answer

The address of an object in the class Rectangle

question

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

answer

True

question

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.

answer

True

question

Which of the following is not true about static methods?

answer

They are called from an instance of the class.

question

Few programmers use wrapper classes because

answer

They are immutable, They are not easy to use

question

The Character wrapper provides numerous methods for

answer

Testing and converting char variables

question

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++; }

answer

ABC

question

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

answer

W

question

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

answer

True

question

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)

answer

True

question

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");

answer

15

question

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

answer

char[ ]

question

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.

answer

trim

question

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

answer

False

question

StringBuffer objects are immutable.

answer

False

question

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

answer

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

question

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");

answer

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

question

When using StringBuffer insert method, you cannot insert

answer

Another StringBuffer type

question

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");

answer

We have lived in Tampa, Trenton, and Atlanta.

question

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

answer

Delimiter

question

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

answer

import java.util.StringTokenizer;

question

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

answer

123, 456 7890, and -

question

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()); }

answer

9

question

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

answer

True

question

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

answer

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

question

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

answer

double x = Double.parseDouble(str);

question

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

answer

String str = Integer.toString(number);

question

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

answer

System.out println(Double.MAX_VALUE);

question

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

answer

False

question

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

answer

They provide static methods that are very useful

question

Use the following import statement when using the character wrapper class

answer

No import statement is needed

question

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++; }

answer

456

question

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

answer

f

question

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);

answer

False

question

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);

answer

-1

question

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);

answer

diddl

question

Two ways of concatenating two strings are

answer

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

question

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

answer

True

question

StringBuffer objects are not immutable.

answer

True

question

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

answer

16 characters

question

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");

answer

strbuff would equal "The cow jumped over the moon"

question

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

answer

The insert will start at position 32

question

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");

answer

We have lived in Chicago, Tampa, and Atlanta.

question

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

answer

Token

question

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

answer

Semicolon

question

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

answer

January, 1, 2004, space, comma

question

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()); }

answer

7

question

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.

answer

False

question

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

answer

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

question

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

answer

integer x = Integer.parseInt(str);

question

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

answer

String str = Double.toString(d);

question

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

answer

System.out.println(Integer.MAX_VALUE);

question

You cannot assign a value to a wrapper class object.

answer

False

question

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

answer

All the characteristics of the general object, plus additional chracteristics

question

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

answer

public class Salaried extends PayType

question

If ClassA is Derived from ClassB, then

answer

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

question

In UML diagrams, inheritance is shown

answer

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

question

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

answer

True

question

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

answer

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

question

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

answer

False

question

A protected member of a class may be directly accessed by

answer

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

question

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

answer

Private Members

question

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

answer

Package

question

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

answer

A chain of inheritance

question

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

answer

True

question

If a class contains an abstract method

answer

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

question

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

answer

True

question

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

answer

ClassB must override each method in ClassA

question

All fields declared in an interface

answer

Are final and static

question

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

answer

"is a"

question

A derived class can directly access

answer

Only Public and protected members of the base class

question

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

answer

ClassB

question

In UML diagrams, inheritance is shown

answer

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

question

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

answer

False

question

If a base class does not have a default constructor,

answer

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

question

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

answer

False

question

Protected members are

answer

Not quite private; Not quite different

question

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

answer

#

question

The difference between protected access and package is

answer

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

question

In a class hierachy

answer

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

question

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

answer

True

question

If a class contains an abstract method,

answer

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

question

All methods in an abstract class must also be declared abstract

answer

False

question

In an interface all methods have

answer

Public access

question

Which of the following statements correctly specifies three interfaces:

answer

public class ClassA implements Interface1, Interface2, Interface3

question

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

answer

False

question

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; } }

answer

38

question

A ragged array is

answer

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

question

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; }

answer

60

question

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]; }

answer

Value contains the lowest value in array1

question

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]; }

answer

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

question

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; }

answer

180

question

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?

answer

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

question

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;

answer

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

question

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;

answer

a = 5

question

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

answer

False

question

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

answer

The array numbers has 6 rows and 9 columns

question

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

answer

All of the above

question

The sequential search algorithm

answer

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

question

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.

answer

True

question

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

answer

True

question

The binary search algorithm

answer

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

question

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

answer

33

question

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

answer

True

question

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

answer

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

question

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]; }

answer

value contains the sum of all the values in array1

question

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

answer

str[0].toUpperCase();

question

In memory, an array of String objects

answer

Consists of an array of references to Stringobjects

question

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

answer

A reference to the String "ghi"

question

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

answer

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

question

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

answer

add

question

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; }

answer

180

question

In order to do a binary search on an array,

answer

The array must first be sorted in ascending order

question

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

answer

set

question

This ArrayList class method deletes an item from an ArrayList.

answer

remove

question

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

answer

True

Java Ch 8 – 11 – Flashcards

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