1.4 Data types, structures and algorithms Flashcards
What is a primitive data type
Basic type is a data type provided by a programming language as a basic building block
What are the common primitive data types (5)
Integer
Floating point/ real
Character
String
Boolean
What do integers hold
Whole numbers
What do floating points/ reals hold
A number with a fractional part
What do characters hold
A single alphanumeric character or special symbol
What do strings hold
Multiple alphanumeric or special symbols
What do booleans hold
The value 0 or 1 sometimes represented by False or True
Why do we use binary
Because computers can only represent values as on or off; because they are reliant on electricity. It is also very reliable ; the computer always receives the correct data.
Why doe we use hexadecimal(4)
Much easier to read than a long string of binary
Quicker to write and take up less space
Less chance of making an error while typing
Very easy to convert to and from binary
What is hexadecimal used for (4)
Colours
MAC addresses
Assembly languages
Machine Code
Define Bit
the smallest unit of data in a computer, holds either a 0 or a 1
Define nibble
A sequence of 4 bits
Define Byte
A sequence of 8 bits
How many bits are required to hold a value of 2^n or below
n
What are the prefixes for bytes
Kilobyte - kB - 10^3
Megabyte - MB - 10^6
Gigabyte - GB - 10^9
Terabyte - TB - 10^9
Kibibyte - kiB - 2^10
Mebibyte - Mib
How do character sets work
Each single alphanumeric and special character is represented by an individual binary value
What is ASCII?
7 bit character set that can hold 128 characters used mostly for english
What is extended ASCII
8 bit character set that can hold 256 characters with extra characters for different langauages
What is Unicode?
16 or 32 bit character set that can hold characters for many languages
What is the comparison operator for equal
==
What is the comparison operator for not equal
<> or !=
What is the comparison operator for greater than
>
What is the comparison operator for less than
<
What is the comparison operator for greater than or equal
> =