Reviews

Question 1

describe the difference between the if/else if statement and a series of if statements

Answer 1

in an if/else if statement, the conditions are tested until one is found to be true. The conditionally executed statements are executed and the program exits if the if/else if statement. In a series of if statements, all of the if statements execute and test their conditions because they are not connected.

Question 2

in an if/else if statement what is the purpose of a trailing else

Answer 2

the trailing else provides code that is executed when none of the conditions in the if/else if statements are true

Question 3

what is a flag and how does it work

Answer 3

a flag is a boolean variable signaling that some conditions exists in the program. When the flag is set to false it indicates the condition does not yet exist. When flag is set to true, it indicated that the condition does exist.

Question 4

can an if statement test expressions other than relational expressions? explain

Answer 4

Yes. The if statement can test any value that yields a boolean value (true or false) or a numeric value. When testing a numeric expression, a nonzero numeric value is considered true, and the the value 0 is considered false.

Question 5

briefly describe how the && operator works

Answer 5

it takes two expressions as operands and creates a single expression that is true only when both subexpressions are true

Question 6

briefly descrive how the || operator works

Answer 6

it takes two expressions as operands and creates a single expression that is true when either of the subepressions are true.

Question 7

why are the relational operaters called relational

Answer 7

because they test for specific relationships between items. The relationships are greater than, less than, equal to, etc.

Question 8

why do most programmers indent the conditionally executed statements in a decision structure?

Answer 8

it visually sets the conditionally-executed statements apart from the surrounding code. This is so you can easily identify the code that is conditionally-executed.

Question 9

An expression using the greater than, less than, greater than, or not equal to operator is called a(n) _____ expression.

Answer 9

relational

Question 10

a relational expression is either ___ or ___

Answer 10

true, false

Question 11

the value of a relational expression is 0 if the expression is ___ or 1 if the expression is _____.

Answer 11

false, true

Question 12

the if statement regards an expressison with the value 0 as ___.

Answer 12

false

Question 13

the if statement regards an expression with a nonzero value as ___.

Answer 13

true

Question 14

for an if statement to conditionally execute a group of statements, the statements must enclosed in a set of ___.

Answer 14

braces

Question 15

in an if/else statement, the if part executes its statement or block if the expression is ___, and the else part executes its statement or block if the expression is ___.

Answer 15

true, false

Question 16

the trailing else in an if/else statement has a similar purpose as the ___ section of a switch statement.

Answer 16

default

Question 17

the if/else if statement is actually a form of the ___ if statement

Answer 17

nested

Question 18

If the sub-expression on the left of the __logical operator is false the right sub-expression is not checked

Answer 18

&&

Question 19

If the sub-expression on the left of the ___ logical operator is true, the right sub-expression is not checked.

Answer 19

||

Question 20

The ___ logical operator has higher precedence than the other logical operators

Answer 20

!

Question 21

the logical operators have ___ associativity

Answer 21

left-to-right

Question 22

the __ logical operators works best when testing a number to determine if it is within range

Answer 22

&&

Question 23

the ___ logical operator works best when testing a number to determine if it is out of range

Answer 23

||

Question 24

A variable with ___ scope is only visible when the program is executing in the block containing the variable’s definition

Answer 24

block

Question 25

You use the ___ operator to determine whether one string object is greater than another string object

Answer 25

strings

Question 26

an expression using the conditional operator is a(n) ___ expression.

Answer 26

conditional

Question 27

the expression that is tested by a switch statement must have an __ value

Answer 27

integer

Question 28

the expression following a case statement must be a(n) ____ ___.

Answer 28

integer constant

Question 29

A program will "fall through" a case section if it is missing the ___ statement.

Answer 29

break

Question 30

why should you indent the statements in the body of a loop

Answer 30

by indenting the statements, you make them stand out from the surrounding code. this helps you to identify at a glance the statements that are conditionally executed by a loop

Question 31

describe the difference between pretest loops and posttest loops

Answer 31

a pretest loop tests its condition before each iteration. a posttest loop tests its loop after each iteration. a posttest loop will always execute at least once

Question 32

why are the statements in the body of a loop called conditionally executed statements

Answer 32

because they are only executed when a condition is true

Question 33

what is the difference between the while loop and the do-while loop

Answer 33

the while loop is a prettest loop, the do-qhile loop is a posttest loop.

Question 34

which loop should you use in situations where you wish the loop to repeat until the test expression is false, and the loop should not execute if the test expression is false to begin with?

Answer 34

the while loop

Question 35

which loop should you use in situations where you wish the loop to repeat until the test expression is false, but the loop should execute at least once?

Answer 35

the do-while loop

Question 36

which loop should you use in situations when you know the number of required iterations?

Answer 36

the for loop

Question 37

why is it critical that counter variable be properly initialized?

Answer 37

a counter variable is used to control or keep track of the number of times a loop iterates. In a loop, the counter is usually incremented or decremented. If the counter variable is not properly initialized, it will not hold the correct number.

Question 38

why is it critical the accumulator variables be properly initialized?

Answer 38

an accumulator is used to keep a running total of numbers. In a loop, a value is usually added to the current value of the accumulator. If it is not properly initialized, it will not contain the correct total.

Question 39

why should you be careful not to place a statement in the body of a for loop that changes the value of the loop's counter variable?

Answer 39

because the for lop has an update expression that normally changes the contents of a counter. If you have code inside that loop, that also changes the counter, the loop will not be able to properly control the value of the counter

Question 40

what header file do you need to include in a program that performs file operations?

Answer 40

fstream