Variables

Question 1

What is Declaring?

Answer 1

When you set or declare the data type and name of the variable. These two properties of a variable do not change.

Question 2

What is Assigning?

Answer 2

When you set the value of the variable. The value of a variable can change

Question 3

What is Accessing

Answer 3

When you retrieve the value of the variable by calling its
name.

Question 4

What does each variable in C++ have?

Answer 4

It has
1. A data type
2. A name
3. A value

Question 5

What are integers?

Answer 5

Integers (also known as int ) are whole numbers. They can be positive or negative.

Question 6

When writing large numbers, what must you NOT do?

Answer 6

You should NOT use a comma when typing large numbers.

Question 7

What are Floating Point Numbers?

Answer 7

Floating Point Numbers (also known as float) are numbers with a decimal. They can be positive or negative.

Question 8

The data type Float only uses 4 bytes? What is the better more sufficient option?

Answer 8

The more sufficient option is double which uses 8 bytes or double the space of a float.

Question 9

What values can a boolean variable take?

Answer 9

A boolean variable (declared as a bool) can only take the value of true and false.

Question 10

What is the boolean value “true” equivalent to?

Answer 10

It is equivalent to 1

Question 11

What is the boolean value “false” equivalent to?

Answer 11

It is equivalent to 0

Question 12

What happens if you use the boolalpha command?

Answer 12

It prints the boolean value true/false instead of it’s association 1/0.

Question 13

What is a string?

Answer 13

A string is a collection of text, numbers or symbols. Strings are always surrounded by quotation marks.

Question 14

What isn’t visible when printing a string?

Answer 14

The quotation marks aren’t printed with the collection of text, numbers or symbols.

Question 15

What are the 2 parts of declaring a variable?

Answer 15

You have to set or declare the data type and the name of the variable. These 2 properties do not change.

Question 16

How do you declare a variable?

Answer 16

To declare a variable type the data type and the name of the variable, you want to create, and a ;

Question 17

When you run the code (string my_var;) what response does C++ give and why?

Answer 17

It sends back the message “ Command was successfully executed.” This is because no value has been assigned to the variable.

Question 18

When naming a variable, what must the starting character be?

Answer 18

The starting character must either be a letter or a underscore.

Question 19

What can the remainder of the variable name be?

Answer 19

The remainder of the variable name can be letters, numbers, or underscores.

Question 20

What set of words cannot be used as the variable name?

Answer 20

The C++ Keywords cannot be used as the name. For example, “my_class” is acceptable however “class” is not acceptable.

Question 21

What are C++ keywords?

Answer 21

C++ keywords are words that are reserved for specific functions or tasks within C++ programs.

Question 22

What is the name of the process of setting the initial value of a variable?

Answer 22

The name of the process is initialization. This process can be done separately after the declaration or you can also combine it into the same statement as the declaration.

Question 23

Since the value stored in the variable can change, what is this process called?

Answer 23

This process is called assigning or re-assigning.

Question 24

What is the assignment operator?

Answer 24

The assignment operator is “=” (the equals sign) which gives a variable a new value

Question 25

What code makes the integer variable “my_int” change from 123 to 321?

Answer 25

int my_int = 123;
cout « my_int « endl;
my_int = 321;
cout « my_int « endl;