Programming Fundamentals

Question 1

Compiler

Answer 1

translate high-level language into machine language

Question 2

levels of programming languages

Answer 2

• higher level language
• assembly language
• machine lanuage
• hardware

Question 3

generations of programming language

Answer 3

• first: machine code → 0,1
• second: assembly language → MV, R1, R2
• third: C++, Java → IF TRUE THEN, END IF;
• fourth: SQL, assorted artificial intelligence language → SELECT FIRST_NAME FROM EMPLOYEE;

Question 4

C++ programming language

Answer 4

• general purpose programming language
• based on keywords
  // → comments
  #include → pre-processor instruction to include code of standard library
  int main(0) → declaration of function
  {…..} → statement specifiying behaviour of program

Question 5

variables

Answer 5

defined in programming language, used to perform operations
- name & type → determines operations possible to perform
- variable declaration: int numberOfStudents;
bool → boolean [TRUE, FALSE]
char → character [‘a’, ‘n’, ‘3’]
int → integer [1, 30, 4578]
double → floating point number [3.29, 1.57]

Question 6

values

Answer 6

assigend to variale name via assignment operator “=”
- variable assignment: numberOfStudents=200;
one might initialise variable when declaring it

Question 7

type sizes

Answer 7

• corresponds directly to hardware facilities
• fixed size that determines range of values that can be stored
  bool → 1 byte (8 bit)
  char → 1 byte
  int → 4 bytes
  double → 8 bytes

Question 8

array data strucutre

Answer 8

store collection of values of a given type

- char v[6] → array of 6 characters → 6 bytes to store character in

Question 9

control structures

Answer 9

selection: decision which pathway is taken → TRUE & FALSE
- if & switch (depending ong implemented case different outcome)
iteration (loop): repeat certain path whilst true
- while → as long as condition is true, command is repeated
- for → repeat for a certain amount
sequence: one command after another

Question 10

function declaration

Answer 10

Functions require a delcaration to be called
- declaration: give the name of the function, type of value returned, number of types of arguments
void exit(int); → int argument and return nothing
double sqrt(double); → double argument & return double
double s2 = sqrt(2); → call sqrt with argument double {2}
double s3 = sqrt("three"); → error

Question 11

motivation for functions

Answer 11

• break up complicated & long computations into meaningful chunks & name them
• coding recommendation for one function: 40 lines/7 lines
  goal: comprehensible

Question 12

Function definitions

Answer 12

• every function must be defined somewhere
• need to be defined once
• function definition is a function declaration in which the body of the function is presented

Question 13

C++ vs. python

Answer 13

python
- young language
- easy use and readability
- "write once, use anywhere"
- has to be interpreted → slower
C++
- more complicated
- easily transferable to wide variety of applications
- need to be complie on application system before it can execute
- nearer to the hardware → faster

Question 14

threshold binary

Answer 14

values above a certain threshold are 1/”TRUE”, values below are 0/”FALSE”
→ loss of information

Question 15

threshold to zero

Answer 15

only values below threshold are 0

→ information is preserved

Question 16

pass by reference

pass by value

Answer 16

pass by reference: change the reference → also change what we defined before
- e.g. double& x
pass by value: copy the value and get a new address; can be changed while the defined value (in the determination) does not change
e.g. int y