COP1334 Chapter 4

This operator takes an operand and reverses its truth or falsehood:

!

Which of the following is evaluated first, given the expression: A && B || C && !D

!D

This operator represents the logical AND:

&&

When a relational expression is false, it has the value.

0

What is assigned to the variable result given the statement below with the following assumptions: x = 10, y = 7, and x, result, and y are all int variables. result = x>=y;

1

What is the output of the following code? int w = 98; int x = 99; int y = 0;int z = 1; if (x >= 99) { if (x < 99) cout << y << endl; else cout << z << endl; } else { if (x == 99) cout << x << endl; else cout << w << endl; }

1

What will be displayed after the following statements execute? int funny = 7, serious = 15; funny = serious % 2; if (funny != 1) { funny = 0; serious = 0; } else if (funny == 2) { funny = 10; serious = 10; } else { funny = 1; serious = 1; } cout << funny << " " << serious << endl;

1 1

After the following code executes, what is the value of my_value if the user enters 0? cin >> my_value; if (my_value > 5) my_value = my_value + 5; else if (my_value > 2) my_value = my_value + 10; else my_value = my_value + 15;

15

Which value can be entered to cause the following code segment to display the message "That number is acceptable"? int number; cin >> number; if (number > 10 && number < 100) cout << "That number is acceptable.\n"; else cout << "That number is not acceptable.\n";

99

The __________ is an equality (or comparison) operator.

==

Without this statement appearing in a switch construct, the program "falls through" all of the statements below the one with the matching case expression.

Break

Relational operators allow you to __________ numbers.

Compare

If you intend to place a block of statements within an if statement, you must place__________ around the block:

Curly braces { }

What is the value of the following expression? true && false

False

After the following code executes, what is the output if user enters 0? int x = -1; cout << "Enter a 0 or 1: "; cin >> x; if (c) cout << "true" << endl; else cout <<"false" << endl;

False statement

A variable, usually a bool or an int, that signals when a condition exists is known as a(n)

Flag

When a program lets the user know that an invalid choice has been made, this is known as:

Input validation

Which line in the following program will cause a compiler error? 1 #include <iostream> 2 using namespace std; 3 int main() 4 { 5 int number = 5; 6 if (number >= 0 && <= 100) 7 cout << "passed.\n"; 8 else 9 cout << "failed.\n"; 10 return 0; 11 }

Line 6

These operators connect two or more relational expressions into one, or reverse the logic of an expression.

Logical

When an if statement is placed within the conditionally-executed code of another if statement, this is known as?

Nesting

This statement uses the value of a variable or expression to determine where the program will branch to.

Switch

If you place a semicolon after the statement: if (x < y)

The compiler will interpret the semicolon as a null statement

What is the output of the following code segment? int x = 5; if (x = 2) cout << "This is true!" << endl; else cout << "This is false!" << endl; cout << "That's all, folks!" << endl;

This is true! That's all folks

The default section of a switch statement performs a similar task similar to the__________ portion of an if/else if statement.

Trailing else

What is the value of the following expression? true && !false

True

What is the value of the following expression? true && true

True

What is the value of the following expression? true || false

True

What is the output of the following code segment if the user enters 90 for the score? cout << "Enter your test score: "; cin >> test_score; if (test_score < 60) cout << "You failed the test." << endl; if (test_score > 60) cout << "You passed the test." else cout << "You need to study harder next time." << endl;

You passed the test

Given the if/else statement: if (a < 5) b = 12; else d = 30; What performs the same operation?

a < 5 ? b = 12 : d = 30;

Given that x = 2, y = 1, z = 0, what will the following cout statement display? cout << "answer = " << (x || !y && z) << endl;

answer = 1

Which statement allows you to properly check the char variable code to determine whether it is equal to a C and then output This is a check?

if (code == "C")

Whereas < is called a relational operator, x < y is called a(n)

relational expression

Which of the following expressions will determine whether x is less than or equal to y?

x <= y

What is the value of donuts after the following statement executes? int donuts = 10; if (donuts = 1) donuts = 0; else donuts += 2;

0

What is the value of donuts after the following statement executes? int donuts = 10; if (donuts != 10) donuts = 0; else donuts += 2;

12

What is the output of the following segment of code if the value 4 is input by the user? int num; int total = 0; cout << "Enter a number from 1 to 10: "; cin >> num; switch (num) { case 1: case 2: total = 5; case 3: total = 10; case 4: total = total + 3; case 8: total = total + 6; default: total = total + 4; } cout << total << endl;

13

What is the output of the following code segment if the user enters 23? int number; cout << "Enter a number: "; cin >> number; if (number > 0) cout << "Hi, there!" << endl; else cout << "Good-bye." << endl;

Hi, there!

Input values should always be checked fora. an appropriate range.

reasonableness and division by zero, if division is taking place

Given the following code segment, what is the output? int x = 1, y = 1, z = 1; y = y + z; x = x + y; cout << "result = " << (x < y ? y : x) << endl;

result = 3

This operator represents the logical OR:

||