Data Types / Binary Flashcards
primitive data type
a basic data type provided by the programming language as a basic building block
types of primitive data types (5)
- integer
- real/float
- boolean
- character
- string
denary
base 10 number. uses the combination of ten symbols to represent any number
binary
base 2 number. uses the combination of 2 symbols (0 or 1) to represent every number
hexadecimal
based 16 number. uses the combination of 16 symbols (10 numbers and 6 letters) to represent every number
why use hexadecimal?
- easier to read/ remember
- quicker to write/type
- less chance of making an error
- easy to convert
uses of hex
- define colours
- in MAC addresses
- in assembly language and machine code
integer
any positive or negative whole number e.g. 3, 0, -14
real (floating point)
a positive or negative number with a fractional component e.g. 0.002 or -1.98
character
Any single letter, symbol, number, character or control character
string
any combination of letters, symbols, numbers, characters or control characters e.g. Hello, £4.56
Boolean
Any true/ false data types which often represent logical situations
Sign magnitude most significant bit
represents + or -
+ = negative
- = positive
0.1
positive
1.0
negative
fixed point binary
positive of the binary point is fixed on the number line
by changing the position of the binary point you can…
increase the size of the number
increase the accuracy of the number
mantissa
the actual number you want to store
exponent
positive of the binary point is fixed on the number line
how to convert floating point binary to denary
1) First work out the denary number in the exponent which tells us that the binary point moves ‘n’ places to the right
2) Write out a new binary weighting line with the point in the right place and then convert into denary
Binary -> denary positive exponent
right
Binary -> denary negative exponent
left
in two’s complement the sign is stored in
the most significant bit
normalising a number
means that there is only one way to represent the number