Programming

Question 1

What does execution mean?

Answer 1

The process by which a computer carries out the instructions of a computer.

Question 2

What do algorithm consist of?

Answer 2

A sequence of unambiguous,step-by-step instructions.

Question 3

What is a program an example of?

Answer 3

An algorithm that has been converted into program code so that it can be executed by a computer.

Question 4

What should a well-written algorithm be?

Answer 4

Free of logical errors and easy to code in any high-level language.

Question 5

Can you give 4 differences between an algorithm and program?

Answer 5

Command words in pseudo-code are written in capital letters,in python they’re written in lower case.
SET…TO(pseudo-code) is replaced in python by an =.
RECEIVE..FROM in pseudo-code is replaced in python by an’input’.
SEND..TO DISPLAY in pseudo-code command in python translates to’print’

Question 6

What are the main similarities between algorithms and programs?

Answer 6

Both use descriptive variable names.
Indentation features in both.
The three programming constructs-sequence,selection and iteration(basic building blocks of both)

Question 7

What are the three programming constructs?

Answer 7

Sequence,selection,and iteration

Question 8

What is a syntax error?

Answer 8

An error that occurs when a rule of the programming language is broken.

Question 9

What will happen if a piece of code isn’t right,for a computer?

Answer 9

It won’t be able to execute it and will flag a syntax error.

Question 10

Why do algorithms use variables?

Answer 10

(named memory locations)to store values.

Question 11

Why are variables important for computers?

Answer 11

They have a variety of uses ,for example controlling the number of times a loop is executed.
When algorithms are converted into programs the computer needs to be told what type of data is stored in each variable.

Question 12

What are data types?

Answer 12

specifies what kind of data it can hold.

Question 13

What are common data types?

Answer 13

Integer,real,Boolean and character

Question 14

What does the data type of a value determine?

Answer 14

The operations that can be performed upon it.

Question 15

What is an integer?

Answer 15

Used to store whole numbers without a fractional part.

Question 16

What is real and what is it sometimes referred to?

Answer 16

Used to store numbers with a fractional part.Real numbers are sometimes referred to as floats.

Question 17

What is Boolean?

Answer 17

Only has two possible values;True and False

Question 18

What is a character?

Answer 18

Used to store a single character or symbol.

Question 19

In pseudo-code what don’t you have to specify?

Answer 19

The data types of variables.

Question 20

Why do data types become much more important once you start programming in a high-level language?

Answer 20

The data type of a variable determines the operations that can be performed on it.

Question 21

How can you put an initial value into a variable?

Answer 21

By..
initialising it when the program is run
reading a value from a keyboard or other device

Question 22

What is initalisation?

Answer 22

the process of assigning an initial value to a variable.

Question 23

What is a assignment statement?

Answer 23

the SET..TO command is used to initialise variables in pseudo-code.

Question 24

Once a variable has been initialised,what happens?

Answer 24

An assignment statement is used to change its value

Question 25

Why should variables always be initalised to a starting value?

Answer 25

Some programming languages won’t execute if the programmer fails to do this;others will do so but may produce some unexpected results.

Question 26

What is a type coercion?

Answer 26

when the data type of a variable gets changed during program execution.

Question 27

What’s a command sequence?

Answer 27

A set of instructions that the computer executes one another in order.

Question 28

What are command sequences usually combined with?

Answer 28

Loops and selection statements.

Question 29

What is the selection construct used to create?

Answer 29

A branch in a program.The computer selects which branch to follow based on the outcome of a condition.

Question 30

What is a definite loop used for?

Answer 30

When you know in advance how often the instructions in the body of the loop are to be repeated.

Question 31

What is a indefinite loop used for?

Answer 31

When the number of times a loop will need to be repeated is not known in advance.

Question 32

why use constants?

Answer 32

• Readability-a named constant makes it clear
• Ability to update-if you need to update the constant value,all you need to do is update the initial value once.
• Compiler optimisation-depending on the compiler,use of named constants can lead to optismisation,either improving performance or reducing memory space.

Question 33

what are constants?

Answer 33

identifiers associated with values that remain fixed during the program’s execution.

Question 34

How can a readability of a code be improved?

Answer 34

• Use descriptive names for variables
• Add blank lines between different blocks to make them stand out
• Add comments that explain what each part of the code does.

Question 35

How can descriptive names be used to improve a programs readability?

Answer 35

Using descriptive identifiers for variables,constants and subprograms help to make their purpose clear.

Question 36

how can indentation be used to improve a programs readability?

Answer 36

makes it easier to see where each block of code starts and finishes.If the indentation is wrong then it can lead to the program not running or producing the expected outcomes.

Question 37

how can white space be used to improve a programs readability?

Answer 37

adding blank lines between different blocks of code makes them stand out.

Question 38

How do write a comment in python and java?

Answer 38

for python
Java:single line comment//
multi-line comment with /and end with /