Topic 1 Programming

Question 1

Describe a data type?

Answer 1

Defined by the values it can take or the operations which can be performed on it.

Question 2

Describe the data type known as integer?

Answer 2

A whole number, positive or negative, including zero

Question 3

Describe the data type known as real / float?

Answer 3

A positive or negative number which can have a fractional part.

Question 4

Describe the data type known as Boolean?

Answer 4

A value which is either true or false

Question 5

Describe the data type known as character?

Answer 5

A single number letter or symbol

Question 6

Describe the data type known as string?

Answer 6

A collection of characters

Question 7

Describe the data type known as Date/Time?

Answer 7

A way of storing a point in time

Question 8

Describe the data type known as records?

Answer 8

A collection of fields each of which could have a different data type

Question 9

Describe the data type known as array?

Answer 9

A finite, indexed set of related elements each of which has the same data type

Question 10

What are user-defined data types?

Answer 10

They are derived from existing data types in order to create a customised data structure

Question 11

Why are user defined data types used?

Answer 11

Ensure that a solution is as memory efficient as possible

Question 12

what is variable declaration?

Answer 12

Allocates a portion of the computers memory to the variable.

Question 13

What is constant declaration?

Answer 13

Same as same as variable declaration but when creating a constant. The value of a constant does not change while the program is running.

Question 14

What is assignment in programming?

Answer 14

Giving a constant or variable a value

Question 15

What is iteration?

Answer 15

The process of repeating a block of code or instruction, this could be definite or indefinite

Question 16

What is selection?

Answer 16

Comparing values and choosing an action based on those values.

Question 17

What is a subroutine?

Answer 17

A named block of code containing a set of instructions designed to perform a frequently used operation.

Question 18

What is definite iteration?

Answer 18

A type of iteration in which the number of repetitions required is known before the loop starts

Question 19

what is indefinite iteration?

Answer 19

A type of iteration in when the number of repetitions required is not known before the loop starts

Question 20

What is nesting in programming?

Answer 20

One structure is placed within another and can be easily be identified by different levels of indentation in code.

Question 21

Why is indentation used in programming?

Answer 21

Easier for humans to understand

Question 22

Why should a programmer use sensible and meaningful identifier names?

Answer 22

Makes it easier for others to understand what the purpose of the named object is within the program

Question 23

How do you perform the MODULO function in C# and what does it do?

Answer 23

Returns the remainder of am integer division. The symbol is: %

Question 24

What is truncation?

Answer 24

Removing the decimal part of a number. Never rounds up.

Question 25

Describe how random numbers work in programming?

Answer 25

A built-in function takes a seed value and uses a series of mathematical operations to arrive at a number. This number is not truly random but pseudorandom

Question 26

How does a computer handle exceptions?

Answer 26

By pausing execution of the program and saving the current volatile state of the program to a system stack before running a section of code called a code block.

Question 27

What are the advantages of subroutines?

Answer 27

Reduces repetition and makes the code more compact making it easier to read.

Question 28

What's the difference and similarities of functions and procedures?

Answer 28

They are both types of subroutines but functions are required to return a value whilst procedures may not.

Question 29

What are parameters and what are they used for?

Answer 29

They are used to pass data between subroutines within programs. They hold pieces of information that the subroutine requires to run.

Question 30

What is an argument?

Answer 30

The actual value passed by a parameter.

Question 31

What is a local variable?

Answer 31

Variables that can be accessed from any part of a program and exist in memory for the entire duration of the program's execution

Question 32

What are stack frames used for?

Answer 32

To store return addresses, parameters and local variables for each subroutine call that occurs during the execution of a program

Question 33

What is the role of stack frames in subroutine calls?

Answer 33

If one subroutine calls another, nesting is said to occur. Each subroutine call will be pushed onto the computer's call stack in the form of a stack frame before the subroutines code begins to execute. When the nested subroutine finishes executing the stack frame is popped from the call stack and the computer uses the information to return to execution of the previous subroutine.

Question 34

What is a recursive subroutine?

Answer 34

One which is defined in terms of itself. There is call to the subroutine itself.

Question 35

What is a stopping condition (Base case)?

Answer 35

The terminating situation in recursion that does not use recursion to produce a result

Question 36

Why are base cases needed?

Answer 36

As the program will never terminate causing stack overflow.

Question 37

What is recursion?

Answer 37

The process in which a block of code that is defined in terms of itself makes a call to itself.