CS 150 Chapter 5 (final)

posttest

A do...while loop is a(n) ____________________ loop, since the loop condition is evaluated after executing the body of the loop.

indexed

A for loop is typically called a counted or ____________________ for loop.

invariant

A loop ____________________ is a set of statements that remains true each time the loop body is executed.

infinite

A loop that continues to execute endlessly is called a(n) ____ loop.

semantic

A semicolon at the end of the for statement (just before the body of the loop) is a(n) ____________________ error.

patch

A software ____________________ is a piece of code written on top of an existing piece of code intended to fix a bug in the original code.

flag

A(n) ____-controlled while loop uses a bool variable to control the loop.

True

Assume all variables are properly declared. The output of the following C++ code is 2 3 4 5. n = 1; while (n < 5) { n++; cout << n << " "; }

False

Assume that all variables are properly declared. The following for loop executes 20 times.

counter-controlled

Consider the following code. int limit; int reps = 0; cin >> limit; while (reps < limit) { cin >> entry; triple = entry * 3; cout << triple; reps++; } cout << endl; This code is an example of a(n) ____ while loop.

EOF-controlled

Consider the following code. (Assume that all variables are properly declared.) cin >> ch; while (cin) { cout << ch; cin >> ch; } This code is an example of a(n) ____ while loop.

continue

If a(n) ____________________ statement is placed in a do...while structure, the loop-continue test is evaluated immediately after this statement.

looping

In ____ structures, the computer repeats particular statements a certain number of times depending on some condition(s).

True

In a counter-controlled while loop, the loop control variable must be initialized before the loop.

False

In a sentinel-controlled while loop, the body of the loop continues to execute until the EOF symbol is read.

pretest

In a while and for loop, the loop condition is evaluated before executing the body of the loop. Therefore, while and for loops are called ____________________ loops.

off-by-one or off-by-1 or off by one or off by 1

In a(n) "____________________" problem, either the loop executes one too many or one too few times.

True

In the case of the sentinel-controlled while loop, the first item is read before the while loop is entered.

nesting or nested

Putting one control structure statement inside another is called ____________________.

125

Suppose j, sum, and num are int variables, and the input is 26 34 61 4 -1. What is the output of the code? sum = 0; cin >> num; for (int j = 1; j <= 4; j++) { sum = sum + num; cin >> num; } cout << sum << endl;

110

Suppose sum and num are int variables, and the input is 18 25 61 6 -1. What is the output of the following code? sum = 0; cin >> num; while (num != -1) { sum = sum + num; cin >> num; } cout << sum << endl;

24

Suppose sum, num, and j are int variables, and the input is 4 7 12 9 -1. What is the output of the following code? cin >> sum; cin >> num; for (j = 1; j <= 3; j++) { cin >> num; sum = sum + num; } cout << sum << endl;

break

The ____ statement can be used to eliminate the use of certain (flag) variables.

do...while or do while or do/while or do-while

The ____________________ loop has an exit condition but no entry condition.

To exit early from a loop. • To skip the remainder of a switch structure.

The ____________________ statement is typically used for two purposes:

True

The control statements in the for loop include the initial statement, loop condition, and update statement.

True

The control variable in a flag-controlled while loop is a bool variable.

False

The following while loop terminates when j > 20. j = 0; while (j < 20) j++;

True

The for loop body executes indefinitely if the loop condition is always ____________________.

istream

The function eof is a member of the data type ____________________.

unsigned

The function srand takes as input a(n) ____________________ int, which acts as the seed for the algorithm.

True

The number of iterations of a counter-controlled loop is known in advance.

False

The statement in the body of a while loop acts as a decision maker.

cstdlib

To generate a random number, you can use the function rand of the header file ____________________.

loop-continue test

What executes immediately after a continue statement in a while and do-while loop?

i = 1;

What is the initial statement in the following for loop? (Assume that all variables are properly declared.) int i; for (i = 1; i < 20; i++) cout << "Hello World"; cout << "!" << endl;

34

What is the next Fibonacci number in the following sequence? 1, 1, 2, 3, 5, 8, 13, 21, ...

25 1

What is the output of the following C++ code? count = 1; num = 25; while (count < 25) { num = num - 1; count++; } cout << count << " " << num << endl;

10 11

What is the output of the following C++ code? int j; for (j = 10; j <= 10; j++) cout << j << " "; cout << j << endl;

155

What is the output of the following C++ code? num = 100; while (num <= 150) num = num + 5; cout << num << endl;

10

What is the output of the following C++ code? num = 10; while (num > 10) num = num - 2; cout << num << endl;

This is an infinite loop.

What is the output of the following loop? count = 5; cout << 'St'; do { cout << 'o'; count--; } while (count <= 5);

40

What is the value of x after the following statements execute? int x = 5; int y = 30; do x = x * 2; while (x < y);

for loop

When a continue statement is executed in a ____, the update statement always executes.

the staement

Which executes first in a do...while loop?

do...while

Which of the following is a repetition structure in C++?

do...while loop

Which of the following loops does not have an entry condition?

do...while loop

Which of the following loops is guaranteed to execute at least once?

srand(time(0)); num = rand() % 50;

Which of the following statements generates a random number between 0 and 50?

do...while

____ loops are called posttest loops.