1Why are user defined variables important
They allow for flexibility to suit specific need within a program
2Define and use non composite types
Represents a single value with no internal subcomponents Ex. INTEGER, BOOLEAN, REAL
Enumerated data types like
Type
Daysofweek = (Monday, tuesday, wednesday)
Pointer data type
pointer uses ^ it points to the adress where a variable is stored using @ you can derreference by using ^
3define and use composite types
Multiple components
TYPE (name)
(variable name): (DATA TYPE)
(variable name): (DATA TYPE)
ENDTYPE
Sets, unorderdered and without duplicates
4Serial files
one after the other in a linear order
Daily logs
marked as deleted without removing it
5Sequential files
arranged sequentially in predefined order
Order management in eccomerce
needs to be copied into another file to delete
6Direct access file
Any data can be retrieved at any time
Can be easily deleted by marking it available
7Hashing algorithm
Achieves direct access, reduce collision by using prime number close to the expected size. Produce seemingly random hashes
Dealing with collisions (Sequential search)(reserved adresses)(linked list accesible from each adress)
8Floating point representation
Mantissa value is maxed when 2 most relevant bits are different
9Protocols are important because?
set rules and conventions that allow for data exchange and communication