question

Like all high-level programming languages, Java provides _ :statements that let you choose actions with alternative courses.

answer

selection statements

question

_ use conditions that are Boolean expressions. A Boolean expression is an expression that evaluates to a Boolean value: true or false. We now introduce Boolean types and relational operators

answer

Selection statements

question

How do you compare two values, such as whether a radius is greater than 0, equal to 0, or less than 0? Java provides __ operators (also known as _ operators), shown in Table 3.1, which can be used to compare two values

answer

six relational, comparison

question

less than or equal to (as relational operator)

answer

<=

question

equal to (as relational operator)

answer

==

Unlock the answer

question

not equal to (as relational operator)

answer

!=

Unlock the answer

question

The _ testing operator is two equal signs (==), not a single equal sign (=). The latter symbol is for _.

answer

equality, assignment

Unlock the answer

question

double radius = 1; System.out.println(radius > 0); this displays:

answer

true

Unlock the answer

question

A variable that holds a Boolean value is known as a

answer

Boolean variable

Unlock the answer

question

A variable that holds a Boolean value is known as a Boolean variable. The boolean _ is used to declare Boolean variables.

answer

data type

Unlock the answer

question

assign true to lightsOn

answer

boolean lightsOn = true;

Unlock the answer

question

True and false are _, just like a number such as 10. They are treated as reserved words and cannot be used as identifiers in the program.

answer

literals

Unlock the answer

question

An _ is a construct that enables a program to specify alternative paths of execution.

answer

if statement

Unlock the answer

question

Java has several types of selection statements: _ if statements, _ if-else statements, _ statements, _ if-else statements, _ statements, and _ expressions.

answer

one-way, two-way, nested if, multi-way, switch, conditional expressions

Unlock the answer

question

A one-way if statement executes an action if and only if the condition is true. The syntax for a one-way if statement is:

answer

if (boolean-expression) { statement; }

Unlock the answer

question

The block braces can be omitted if they enclose a _. For example, the following statements are equivalent. if (i > 0) System.out.println("i is positive");

answer

single statement

Unlock the answer

question

(1) If the number is a multiple of 5, the program displays HiFive. If the number is divisible by 2, it displays HiEven. (Just write if statement)

answer

if (number % 5 == 0)

Unlock the answer

question

An _ statement decides the execution path based on whether the condition is true or false.

answer

if-else

Unlock the answer

question

The inner if statement is said to be _ inside the outer if statement.

answer

nested

Unlock the answer

question

style, called _, avoids deep indentation and makes the program easy to read

answer

multi-way if-else statements

Unlock the answer

question

The following errors are common among new programmers. Common Error 1: forgetting _

answer

Forgetting Braces

Unlock the answer

question

Common Error 2: Wrong Semicolon at the

answer

if Line

Unlock the answer

question

if (radius >= 0); same as if (radius >= 0) { } What type of error is this?

answer

empty block

Unlock the answer

question

if (radius >= 0); same as if (radius >= 0) { }. This mistake is hard to find, because it is neither a compile error nor a runtime error; it is a _.

answer

logic error

Unlock the answer

question

Common Error 3: Redundant Testing of

answer

Boolean Values

Unlock the answer

question

if (even == true) is redundant. Better:

answer

if (even)

Unlock the answer

question

if (even = true) is wrong but even so, won't show a _ error. Should be:

answer

compile, ==

Unlock the answer

question

Common Error 4: __ Ambiguity

answer

Dangling else

Unlock the answer

question

Common Error 5: _of Two Floating-Point Values

answer

Equality Test

Unlock the answer

question

double x = 1.0 - 0.1 - 0.1 - 0.1 - 0.1 - 0.1; System.out.println(x == 0.5); Here, x is not exactly 0.5, but is 0.5000000000000001. You cannot reliably test equality of two _ values.

answer

floating-point

Unlock the answer

question

you can compare whether they are close enough by testing whether the difference of the two numbers is less than some threshold. That is, two numbers x and y are very close if |x?y| ; e for a very small value, e. e, a Greek letter pronounced _, is commonly used to denote a very small value

answer

epsilon

Unlock the answer

question

Normally, you set e to _for comparing two values of the double type and to _ for float

answer

1E-14, 1E-7

Unlock the answer

question

setup the EPSILON variable for a floating variable

answer

final double EPSILON = 1E-14;

Unlock the answer

question

if statement to check whether 0.5000000000000001 (x) is approximately 0.5

answer

if (Math.abs(x - 0.5) ; EPSILON)

Unlock the answer

question

delete

answer

d

Unlock the answer

question

The _ method can be used to return the absolute value of a

answer

Math.abs(a)

Unlock the answer

question

improve: Often, new programmers write the code that assigns a test condition to a boolean variable like the code in (a): if (number % 2 == 0) even = true; else even = false;

answer

boolean even = number % 2 == 0;

Unlock the answer

question

You can use _ to obtain a random double value between 0.0 and 1.0, excluding 1.0.

answer

Math.random()

Unlock the answer

question

The previous programs generate random numbers using System.currentTimeMillis(). A better approach is to use the random() _ in the Math _.

answer

method, class

Unlock the answer

question

A better approach is to use the random() method in the Math class. Invoking this method returns a random value of the type _.

answer

double

Unlock the answer

question

_ returns a random single-digit integer (i.e., a number between 0 and 9).

answer

(int)(Math.random() * 10)

Unlock the answer

question

// 1. Generate a random single-digit integer, number1 between 1-10

answer

int number1 = (int)(Math.random() * 10);

Unlock the answer

question

// If number1 ; number2, swap number1 with number2. First line in program (ignoring setup parameters)

answer

if (number1 ; number2) {

Unlock the answer

question

// If number1 ; number2, swap number1 with number2 line 2

answer

int temp = number1;

Unlock the answer

question

// If number1 ; number2, swap number1 with number2 line 3

answer

number1 = number2;

Unlock the answer

question

// If number1 ; number2, swap number1 with number2 line 4 (Swap)

answer

number2 = temp;

Unlock the answer

question

// If number1 ; number2, swap number1 with number2 line 5: the closing line

answer

}

Unlock the answer

question

_ (line 53) is defined in the System class. Invoking this method terminates the program. The status 0 indicates that the program is terminated normally. A nonzero status code indicates abnormal termination.

answer

System.exit(status)

Unlock the answer

question

System.exit(status) (line 53) is defined in the System class. Invoking this method terminates the program. The status 0 indicates that the program is terminated _.

answer

normally

Unlock the answer

question

System.exit(status) (line 53) is defined in the System class. Invoking this method terminates the program. A _ status code indicates abnormal termination.

answer

nonzero

Unlock the answer

question

An initial value of 0 is assigned to tax (line 20). A _ error would occur if it had no initial value, because all of the other statements that assign values to tax are within the if statement. The compiler thinks that these statements may not be executed and therefore reports a compile error.

answer

compile

Unlock the answer

question

For all programs, you should write a small amount of code and test it before moving on to add more code. This is called _ development and testing

answer

incremental

Unlock the answer

question

_ operators, also known as Boolean operators, operate on Boolean values to create a new Boolean value.

answer

Logical

Unlock the answer

question

the __ operator, which negates true to false and false to true.

answer

not (!)

Unlock the answer

question

The __ of two Boolean operands is true if and only if both operands are true

answer

and (;;)

Unlock the answer

question

The __ of two Boolean operands is true if at least one of the operands is true

answer

or (||)

Unlock the answer

question

The __ of two Boolean operands is true if and only if the two operands have different Boolean values

answer

exclusive or (^)

Unlock the answer

question

Note that p1 ^ p2 is the same as _

answer

p1 != p2

Unlock the answer

question

!

answer

logical negation

Unlock the answer

question

;;

answer

logical conjunction

Unlock the answer

question

||

answer

logical disjunction

Unlock the answer

question

^

answer

logical exclusion

Unlock the answer

question

Example (assume age = 24, weight = 140) is false, because (age ; 18) is _.

answer

!(age ; 18), true

Unlock the answer

question

_ is true, because (weight == 150) is false.

answer

!(weight == 150)

Unlock the answer

question

(age ; 18) _ (weight ;= 140) is true, because (age ; 18) and (weight ;= 140) are both true

answer

;;

Unlock the answer

question

(age ; 34) _ (weight ;= 150) is false, because (age ; 34) and (weight ;= 150) are both false

answer

||

Unlock the answer

question

(age ; 18) _ (weight 18) is true.

answer

|| (or operator)

Unlock the answer

question

(age ; 34) ^ (weight ; 140) is _, because (age ; 34) and (weight ; 140) are both false.

answer

false

Unlock the answer

question

(age ; 34) ^ (weight ;= 140) is _, because (age ; 34) is false but (weight ;= 140) is true

answer

true

Unlock the answer

question

if (number % 2 == 0 || number % 3 == 0) System.out.println(number + "__"); ;;;

answer

is divisible by 2 or 3

Unlock the answer

question

if (number % 2 == 0 ^ number % 3 == 0) System.out.println(number + "is __");

answer

divisible by 2 or 3 but not both

Unlock the answer

question

1 ;= no ;= 31 should be

answer

(1 ;= no) ;; (no ;= 31)

Unlock the answer

question

In mathematics, the expression 1 ;= numberOfDaysInAMonth ;= 31 is correct. However, it is incorrect in Java, because 1 ;= numberOfDaysInAMonth is evaluated to a __, which cannot be compared with 31.

answer

boolean value

Unlock the answer

question

_'s law, named after Indian-born British mathematician and logician can be used to simplify Boolean expressions. The law states: !(condition1 && condition2) is the same as !condition1 || !condition2 !(condition1 || condition2) is the same as !condition1 && !condition2

answer

De Morgan

Unlock the answer

question

!(number == 2 || number == 3) is better written as

answer

number != 2 && number != 3

Unlock the answer

question

In programming language terminology, && and || are known as the _ or _ operators

answer

short-circuit, lazy

Unlock the answer

question

A year is a leap year if it is divisible by 4 but not by 100, or if it is divisible by 400. Collect the input for year:

answer

int year = input.nextInt();

Unlock the answer

question

Generate a lottery number (0-100) & call the variable lottery

answer

int lottery = (int)(Math.random() * 100);

Unlock the answer

question

enter a guess of lottery number

answer

int guess = input.nextInt();

Unlock the answer

question

A _ statement executes statements based on the value of a variable or an expression.

answer

switch

Unlock the answer

question

Here is the full syntax for the switch statement: switch (switch-expression) { case value1: statement(s)1; ___; ...

answer

break

Unlock the answer

question

Here is the full syntax for the switch statement: switch (switch-expression) { ___ statement(s)1; break; case value2: statement(s)2; break; ... case valueN: statement(s)N; break; default: statement(s)-for-default; }

answer

case value1:

Unlock the answer

question

Here is the full syntax for the switch statement: switch (switch-expression) { case value1: statement(s)1; break; case value2: statement(s)2; break; ... case valueN: statement(s)N; break; __ }

answer

default: statement(s)-for-default;

Unlock the answer

question

Here is the full syntax for the switch statement: ____ case value1: statement(s)1; break; case value2: statement(s)2; break; ... case valueN: statement(s)N; break; default: statement(s)-for-default; }

answer

switch (switch-expression) {

Unlock the answer

question

The value1, . . ., and valueN must have the same __ as the value of the switchexpression. Value1, . . ., & valueN are ___ expressions, meaning that they cannot contain variables, such as 1 + x.

answer

data type, constant

Unlock the answer

question

When the value in a case statement matches the value of the switch-expression, the statements starting from this case are executed until either a _ _ or the end of the switch statement is reached

answer

break statement

Unlock the answer

question

The _ which is optional, can be used to perform actions when none of the specified cases matches the _.

answer

default case, switch-expression

Unlock the answer

question

The _ case, which is _, can be used to perform actions when none of the specified cases matches the switch-expression

answer

default, optional

Unlock the answer

question

The keyword break is _. The break statement immediately ends the switch statement.

answer

optional

Unlock the answer

question

Do not forget to use a break statement when one is needed. Once a case is matched, the statements starting from the matched case are executed until a _ statement or the __ statement is reached

answer

break, end of the switch

Unlock the answer

question

Do not forget to use a break statement when one is needed. Once a case is matched, the statements starting from the matched case are executed until a break statement or the end of the switch statement is reached. This is referred to as _.

answer

fall-through behavior

Unlock the answer

question

To avoid programming errors and improve code maintainability, it is a good idea to put a _ in a case clause if break is purposely omitted.

answer

comment

Unlock the answer

question

A __ evaluates an expression based on a condition

answer

conditional expression

Unlock the answer

question

if (x > 0) y = 1; else y = -1; Alternatively, as in the following example, you can use a conditional expression to achieve the same result.

answer

y = (x > 0) ? 1 : -1;

Unlock the answer

question

Conditional expressions are in a completely different style, with no explicit if in the statement. The syntax is:

answer

boolean-expression ? expression1 : expression2;

Unlock the answer

question

Suppose you want to assign the larger number of variable num1 and num2 to max. You can simply write a statement using the conditional expression:

answer

max = (num1 > num2) ? num1 : num2;

Unlock the answer

question

The symbols ? and : appear together in a conditional expression. They form a _ and also called a _ operator because it uses three operands.

answer

conditional operator, ternary (It is the only ternary operator in Java.)

Unlock the answer

question

Operator _ and _ determine the order in which operators are evaluated.

answer

precedence, associativity

Unlock the answer

question

If operators with the same precedence are next to each other, their associativity determines the order of evaluation. All binary operators except assignment operators are __.

answer

left associative

Unlock the answer

question

Assignment operators are right associative. Therefore, the expression a = b += c = 5 is equivalent to

answer

a = (b += (c = 5))

Unlock the answer

question

Finding logic errors, on the other hand, can be very challenging. Logic errors are called _. The process of finding and correcting errors is called debugging

answer

bugs

Unlock the answer

question

A common approach to debugging is to use a combination of methods to help pinpoint the part of the program where the bug is located. You can _ the program (i.e., catch errors by reading the program), or you can insert print statements in order to show the values of the variables or the execution flow of the program.

answer

hand-trace

Unlock the answer

question

JDK includes a command-line debugger, _, which is invoked with a class name. _ is itself a Java program, running its own copy of Java .

answer

jdb, interpreter

Unlock the answer

question

__: The debugger lets you trace all of the method calls. This feature is helpful when you need to see a large picture of the program-execution flow.

answer

Displaying call stacks

Unlock the answer

Java Chapter 3 Test Questions – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards