SDD : Computational constructs

Question 1

Global Variables

Answer 1

Global variables - accessed by every sub-program or module at all times. Always present in RAM during execution

Question 2

Local Variables

Answer 2

Local variables - only accessed within the sub-program that they have been declared/created within. Only present in RAM during the execution of the sub-program where they are located

Question 3

Disadvantages of gobal variables

Answer 3

Subroutines can change the variables by accident

Question 4

Adavtages of local variables

Answer 4

More effecient in terms of memory

Removes naming clashes with other local variables in other subroutines

Question 5

Actual parameters

Answer 5

Passes in to subroutines

Question 6

Formal parametres

Answer 6

def addnumber ( FORMAL PARAMETRES)

Question 7

Subprograms/routines

Answer 7

A sub-program is a block of code that can be called and accessed by a main program

Question 8

Functions

Answer 8

are sub-programs designed to return value(s) which can be assigned to a variable

Question 9

Procedures

Answer 9

Procedures are sub-programs designed to perform a series of commands with values sometimes passed to another part of the program

Question 10

Converting character to ASCII

Answer 10

ord(“a)

Question 11

converting ascii to character

Answer 11

chr(“a)

Question 12

converting floating point numbers to substrings

Answer 12

original=24.54

int(original)

Question 13

Substrings

Answer 13

[start:stop:step}