ITSC Chapter 4

This operator performs a logical NOT operation:

!

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

!

This operator represents the logical AND:

&&

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

0

What will the following program display? #include <iostream> using namespace std; int main() { int a = 0, b = 2, x = 4, y = 0; cout << (a == b) << " " cout << (a != b) << " " cout << (b <= x) << " " cout << (y > a) << endl; return 0; }

0 1 1 0

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

After execution of the following code, what will be the value of input_value if the value 0 is entered at the keyboard at run time? cin >> input value; if (input_value > 5) - input_value = input_value + 5; else if (input_value > 2) - input_value = input_value +10; else - input_value = input_value + 15

15

What will be the value of result after the following code has been executed? int a = 60; int b = 15; int result = 10; if (a = b) result *= 2

20

What is the output of the following segment of code if the value 4 is input by the user when asked to enter a number? 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;

28

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

3

Assuming x is 5, y is 6, and z is 8, which of the following is false? 1. x ==5; 2. 7 <= (x + 2); 3. z < = 4; 4. (1 + x) := y; 5. z >=8; 6. x >= 0; 7. x <= (y * 2)

3 and 4 are false

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

8

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 acceptable. \n";

99 (since it's between 11 and 99)

This operator is used in C++ to represent equality

==

Input values should always be checked for:

Appropriate range, reasonableness, division by 0.

What will the following segment of code output if the value 11 is entered at the keyboard? int number; cin >> number; if (number > 0) cout << "C++"; else cout << "Soccer"; cout << " is "; cout << "fun" << endl;

C++ is fun

Relational operators allow you to _______ numbers.

Compare

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

Curly braces { }

This is a variable, usually a bool or an int, that signals when a condition exists.

Flag

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

Nesting

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

Relational expression

What will the following segment of code output? score = 40; if (score > 95) cout << "Congratulations!\n"; cout << "That's a high score:\n"; cout << "This is a test question!" << endl;

That's a high score This is a test question!

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

The compiler will intercept 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 flase!" << endl; cout << "This is all folks!" << endl;

This is true! This is all folks!

True/false: An expression that has any value other than 0 is considered true by an if statement.

True

True/false: If the sub-expression of the left side of the || operator is true, the expression on the right side will not be checked.

True

What will the following segment of code output? Assume the user enters a grade of 90 from the keyboard. cout << "Enter a test score: "; cin >> test_score; if (test_score < 60); cout << "You failed the test!" << endl; if (test_score > 60) cout << "You passed the test!" << endl; else cout << "You need to study for the next test";

You failed the test! You passed the test!

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

answer = 1

In C++ the = operator indicates:

assignment

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

What will be the output of the following code segment after the user enters 0 at the keyboard? int x = -1 cout << "Enter a 0 or a 1 from the keyboard: "; cin >> x; if (x) cout << "true" << endl; else cout << "false" << endl;

false

True/false: The default section is required in a switch statement

false The default section is *OPTIONAL* in a switch statement

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" and then advance to a new line?

if (code == "C") cout << "This is a check\n";

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

input validation

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

logical

The ______ of a variable is limited to the block in which it is declared

scope

This statement used the value of a variable or expression to determine where the program will branch to:

switch

The default section of a switch statement performs a similar task as the ______ portion of an if/else if statement:

trailing else

True/false: Both of the following if statements perform the same operation. if (sales > 10000) commissionRate = 0.15; if (sales > 10000) commissionRate = 0.15;

true

True/false: You should be careful when using the equality operator to compare floating point values because of potential round-off errors.

true

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

true

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

true

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

x <= y

This operator is known as the logical OR operator:

||