Lecture 2

Question 1

A C++ program is a collection of?

Answer 1

Functions

Question 2

What type of function is always in a C++ program?

Answer 2

main() which is always executed first

Question 3

What are the other functions beside main() called and when are they executed?

Answer 3

Other functions in the program are
subprograms and are not executed until they
are called

Question 4

What is a statement and what does this end in?

Answer 4

An instruction that ends with a semi-colon

Question 5

What is a block?

Answer 5

Any section of code which is surrounded by curly brackets is a block

e.g. A block of 4 statements

{
cout «“A fraction: “«5.0/8.0 «endl;
cout «“Big # : “&laquo_space;7000.0*7000.0«endl;
cout «8 + 5 «” is the sum of 8 & 5\n”;
cout &laquo_space;“Hello world”;
}

Question 6

What are the types of information a computer uses?

Answer 6

Simple (needs little or no effort to use)
* To hold whole numbers (integers)
* To hold numbers with fractions (float and double)
* To hold individual characters (char)

Complex (needs a little more work to use)
* Strings
* cin and cout

Question 7

What is the difference between char(acter) and string?

Answer 7

Char is single characters, string is a lot of characters

Question 8

What does a C++ program normally need to do?

Answer 8

1. Reserving and labelling some space to store
   information
2. Getting information like int or string into the space you reserved
3. Doing something (operate on) with the information (int, float, double, char or string)
4. Displaying results

Question 9

What is constant?

Answer 9

A fixed value represented by something e.g. π

Question 10

What is a variable

Answer 10

A value that can change

Question 11

What is a literal?

Answer 11

A fixed value that represents itself, e.g. 2 or 7

Question 12

What can you categorise information as?

Answer 12

• constant
• variable
• literal

Question 13

How does information of variable, constant and literals get into the computer?

Answer 13

We enter values of literals and constants directly into code but for constants we instruct the computer to reserve space for a constant.

We instruct the computer to reserve space for a variable. We have a choice on how we enter
values of variables. We can enter values directly in code or can be set interactively with a user.

Question 14

What are the named areas of memory called?

Answer 14

Variables and Constants

Question 15

What is a declaration?

Answer 15

When the computer is instructed to
reserve space for information and at the same time tell the computer the name that will be used to refer to that bit of information

Question 16

What happens when a variable is declared?

Answer 16

The computer marks the bit of memory reserves so that it allows its contents to change at any time

Question 17

What happens when a constant is declared?

Answer 17

The computer effectively locks the memory reserved and prevents the contents being updated.

Question 18

What are the rules to creating a variable?

Answer 18

<type> <identifier>:
needs to be assign at some point
</identifier></type>

Question 19

What are the rules to creating a constant?

Answer 19

const <type> <identifier> = <value>;</value></identifier></type>

<type>
choose one data type such as int or float
<identifier>
You create a name. It must obey the rules for
identifiers
<value>
You provide the constant value e.g. for Pi value was 3.142
</value></identifier></type>

Question 20

What are the rules to creating a identifier?

Answer 20

An identifier must start with a letter or underscore, and the spaces should be replaced with underscores

Question 21

What can’t be identifiers?

Answer 21

Reserved words such as if else or return which have meanings in C++, using these will cause an error