selection

Question 1

Selection Statements Used to allow your program to

Answer 1

“think” and make logical choices

Question 2

Logical expressions are used to provide decision-making ability
a they protect the body of a selection statement.

Answer 2

In other words,
you will ONLY perform the body of a selection statement if the logical
expression evaluates to TRUE.

Question 3

The body of a selection statement uses the

Answer 3

same brackets as the main
function {}. These brackets denote the start and end of a selection
statement.

Question 4

You can put anything that you want inside of the body of a selection
statement (Ex. Declare variables, do output, ask for input, etc.).

Answer 4

However, they will only be valid within the body of the selection
statement. In other words, once you leave the body it no longer exists.

Question 5

Independent IF Statements

- Each independent IF statement is processed

Answer 5

and evaluated independently

of any other statements.

Question 6

Syntax if

Answer 6

if(Logical Expression)
{
Statement(s)
}

Question 7

• Example:
  int temp = 0;

        temp = 27;

Answer 7

if(temp <= 32)
{
cout &laquo_space;“It is cold outside.” &laquo_space;endl;
}

		if(temp <= 55)
		{
			cout << "It is cool outside." << endl;
		}

Question 8

IF/ELSE Statements

- The IF and ELSE are

Answer 8

dependent on each other
You must choose one or the other. If the first one is true,
then the second one must be false and vice versa

Question 9

The else statement acts as the

Answer 9

default and therefore NEVER needs

a logical expression.

Question 10

IF/ELSE Statements syntax

Answer 10

if(Logical Expression)
				{
					Statement(s)
				}
				else
				{
					Statement(s)
				}

Question 11

-Example:
int temp = 0;
temp = 27;

Answer 11

if(temp <= 32)
			{
				cout << "It is cold outside." << endl;
			}
			else
			{
				cout << "It is not that cold outside." << endl;
			}

Question 12

IF/ELSE IF/ELSE Statements

- This works similar to the IF/ELSE

Answer 12

This is used when you want to extend the number of options
to choose from. You can add as many “else if” as needed
to increase the number of choices.

Question 13

Each ELSE IF has its own

Answer 13

logical expression

Question 14

The IF, ELSE IF(s) and ELSE are all

Answer 14

dependent on each other
- You must choose one from the group. The first one that is
evaluated to true is selected even if other logical expressions
in the group are true as well

Question 15

The else statement acts as the default

Answer 15

and therefore NEVER needs

a logical expression.

Question 16

IF/ELSE IF/ELSE syntax

Answer 16

if(Logical Expression #1)
				{
					Statement(s)
				}
				else if(Logical Expression #2)
				{
					Statement(s)
				}
				else if(Logical Expression #3)
				{
					Statement(s)
				}
				else
				{
					Statement(s)
				}

Question 17

IF/ELSE IF/ELSE  syntax 
Example:
			int temp = 0;
			temp = 45;
			if(temp <= 45)

Answer 17

{
cout &laquo_space;“It is cold outside.” &laquo_space;endl;
}
else if(temp >= 85)
{
cout &laquo_space;“It is hot outside.” &laquo_space;endl;
}
else
{
cout &laquo_space;“It is nice outside.” &laquo_space;endl;
}

Question 18

Example #1 - Write a selection statement that will display "You passed"
	//if the user enters a grade greater than or equal to 70. Write a selection
    //statement that will display "Perfect Score" if the user enters a grade 
	//greater than or equal to 100.

Answer 18

double grade = 0; //Declare variable
cout &laquo_space;“Enter your grade: “; //Request
cin&raquo_space; grade; //Response

	//Check for grade GTE 70
	if(grade >= 70)
	{
		cout << "You passed" << endl;
	}

	//Check for grade GTE 100
	if(grade >= 100)
	{
		cout << "Perfect Score" << endl;
	}

Question 19

//Example #2 - Write a selection statement that allows the
    //user to choose either door #1 or door #2.
	//Display the users selection.

Answer 19

int door = 0; //Declare variable
cout &laquo_space;“Please choose a door (1 or 2): “; //Request
cin&raquo_space; door; //Response

	//Check for door #1 or door #2
	if(door == 1)
	{
		cout << "You chose door #1." << endl;
	}
	else
	{
		cout << "You chose door #2." << endl;
	}

Question 20

//Example #3 - Write a selection statement that allows the
    //user to choose either door #1, door #2, or door #3. If the
	//user chooses an invalid selection, display "Invalid choice".
	//Display the users selection.

Answer 20

int door = 0; //Declare variable
cout &laquo_space;“Please choose a door (1, 2, or 3): “; //Request
cin&raquo_space; door; //Response

	//Check for door #1, door #2, door #3, or invalid choice
	if(door == 1)
	{
		cout << "You chose door #1." << endl;
	}
	else if(door == 2)
	{
		cout << "You chose door #2." << endl;
	}
	else if(door == 3)
	{
		cout << "You chose door #3." << endl;
	}
	else 
	{
		cout << "Invalid choice" << endl;

Question 21

/Example #4 - Write a selection statement that allows the
    //user to choose an operation by entering the symbol (+, -, *, /).
	//If the user chooses an invalid selection, display "Invalid operation".
	//Display the users selection.

Answer 21

char op = ‘ ‘; //Declare variable
cout &laquo_space;“Please select an operaton (+, -, *, /): “; //Request
cin&raquo_space; op; //Response

	//Check for +, -, *, /, or invalid operation
	if(op == '+')
	{
		cout << "You chose addition." << endl;
	}
	else if(op == '-')
	{
		cout << "You chose subtraction." << endl;
	}
	else if(op == '*')
	{
		cout << "You chose multiplication." << endl;
	}
	else if(op == '/')
	{
		cout << "You chose division." << endl;
	}
	else 
	{
		cout << "Invalid operation." << endl;
	}