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Data Types - Coggle Diagram

- - - - Array requires loop for simple tasks
  - - - Commonly
        
        assignment
        
        catenation
        
        comparison for equality and inequality
        
        slices
    - - Data elements have pre defined type
      - element is identified by its position
    - - One-dimensional arrays - Vector
        
        if run time checking done, attributes are static
        
        only access function required
        
        descriptor not required
        
        can be accessed by using the function
        
        value can be computed if statically bound
      - Two-dimensional arrays - Matrix
        
        row major order
        
        address is base address of structure
      - Multi-dimensional arrays
        
        Rectangular and Jagged Arrays
        
        Rectangular array
        
        all rows have same number and all columns too
        
        Jagged Array
        
        Lengths no need to be same
        
        Associative Array
        
        only design issue that is specific for associative arrays is the form of references to their elements.
    - - Heap Dynamic Array
        
        Binding is dynamic in heap
      - Static Array
        
        statically bound and static allocation
        
        Size known at compile time
      - Fixed Stack- Dynamic Array
        
        Space Efficient
        
        Size known at compile time
      - Fixed Heap Dynamic
        
        Binding done during request
        
        Allocated from heap which is longer than stack
    - - Depends on language some allow initialisation in declaration
      - C & C++ implement string as a char array
  - - - Basic Operations
        
        can be simulated with integer but may have issues
        
        could be assigned any value
        
        rarely intended
        
        no type checking
      - constants implicitly start from 0,1 but can be reassigned
      - ordered list of distinct values
      - Advantages
        
        Enhanced Readability
        
        No arithmetic operations
  - - - Info
        
        True may be 1 or -1 or any other non-zero value
        
        False is 0
        
        Single bit can be used
        
        Can have either true or false
      - History
        
        Introduced in Algol 60
        
        Simplest data type
      - About
        
        Logical data type
        
        Represents true and false
    - - Stored as numeric codes
      - Single character as value
      - Most commonly used
        
        8-bit ascii
        
        Iso 8859-1
        
        Unicode
      - Each character assigned to different number
    - - Fixed point
        
        Store fixed number of decimal digits with fixed position for decimal point
        
        Advantages
        
        High precision
        
        Disadvantages
        
        Restricted range (no exponents)
      - Integers
        
        Storage representation
        
        Unsigned
        
        Signed
        
        Two's complement
        
        Sign magnitude
        
        One's complement
        
        Operations on integer data
        
        Arithmetic
        
        Binary
        
        Unary
        
        Relation
        
        Assignment
        
        Bit operation
      - Floating point
        
        Types
        
        Float
        
        Standard size usually 4 bytes
        
        Double
        
        2x space of float
        
        Larger range
        
        Are signed and can have both negative and positive values
        
        Representation
        
        Computer
        
        Exponent & mantissa
        
        IEEE floating point standard 754
        
        Issues
        
        Loss of accuracy
      - Complex
        
        Descriptors
        
        Used for type checking and building code
        
        Used by run-time system if dynamic
        
        Collection of attributes of variables
  - - - About
        
        Describe Text patterns
        
        Characters have own syntax
        
        aka
        
        regexp
        
        regex
        
        matching text done by Regex Engine
      - Basic Elements
        
        Position indicators
        
        Character sets
        
        Quantifiers
      - Anchors
        
        Regex Engine stops after first match
      - Character sets
        
        Character classes
        
        [xy] - x or y
        
        [a-z] - a or b or ……z
        
        etc.
      - Quantifiers
        
        Specify repetition
        
        generally applies to preceded item
    - - String length
        
        Limited dynamic length strings
        
        Adjacent storage cells
        
        Faster operations
        
        Less storage required
        
        But not practical with increasing string size
        
        Pointer array
        
        Faster than linked list
        
        Extra memory
        
        Linked list
        
        But simpler allocation and deallocation
        
        Extra storage
        
        Complex operations
- - - - Similar motivation to process abstraction
      - Can declare variables even though type is hidden
      - Unnecessary details of type can be hidden
        
        Process abstraction
      - Data abstraction
  - - - Data sorted into sets
      - Operations modeled by function
      - Tests modelled by
        
        Relations on the sets
        
        Functions on the set
  - - - Fortran
        
        Linked list and binary tree implemented with arrays
      - Cobol
        
        Allow programmers to specify accuracy
        
        Structured data type for information record
      - Algol 68
        
        Few basic types
        
        Few flexible structure defining operators