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Data Types - Coggle Diagram

- - - - Descriptor required only during compilation has
        
        Address of first character
        
        Name of type
        
        Type length
      - Limited dynamic length strings
        
        Require run-time descriptor except in C & C++
        
        Stores
        
        Fixed max length
        
        Current length
        
        Require more complex storage management
        
        Pointer array
        
        Faster than linked list
        
        Extra memory
        
        Adjacent storage cells
        
        Faster operation
        
        Less storage required
        
        But not practical with increasing string size
        
        Linked lists
        
        Simple allocation & deallocation
        
        Extra storage
        
        Complex operations
      - Dynamic length strings
    - - Catenation
      - Substring selection
      - Comparison
      - Assignment
      - Pattern matching
  - - - Rectangular and Jagged array
        
        A rectangular array is a multi-dimensioned array (rectangular tables) in which all of the rows have the same number of elements and all of the columns have the same number of elements
    - - Fixed Stack-Dynamic arrays
        
        Subscript ranges are statically bound, But the storage allocation is done at declaration elaboration time during execution
      - Fixed Heap Dynamic arrays
        
        Subscript ranges and the storage binding are both fixed after storage is allocated.
      - Static arrays
        
        Subscript ranges are statically bound and storage allocation is static (done before run time)
      - Heap-dynamic arrays
        
        The binding of subscript ranges and storage allocation is dynamic in heap Can change at any time during the array’s lifetime
    - - Unordered collection of data elements that are indexed by an equal number of values called keys
  - - - Operations
        
        Binary
        
        Unary
        
        Arithmetic
        
        Relation
        
        Assignment
        
        Bit operation
      - Storage representation
        
        Unsigned
        
        Signed
        
        Sign magnitude
        
        One's complement
        
        Two's complement
      - Differences in Integer data type
        
        May/May not allow negative
        
        Size variation
        
        Different machines
        
        Languages
      - Representation
        
        Computer
        
        Hardware support
        
        Not supported
        
        Real world
    - - Computer Representation
        
        Signed and can have both positive & negative values
        
        Represented as fractions and exponents
        
        Same operation as integer
        
        Numbers are rarely equal due to round-off
        
        Boolean operations are rstricted
        
        Smaller computers don't have hardware support but can emulate with software
        
        Types
        
        Double
        
        2x space of float
        
        Larger range
        
        Float
        
        Standard size usually 4 bytes
        
        Differ regarding domain
        
        Precision is accuracy
        
        Range is combination of range of fractions and components
      - Issues
        
        Only approximation
        
        Stored in binary
        
        Loss of accuracy
      - Representation
        
        Real world
        
        Real numbers
        
        Computer
        
        Exponent & Mantissa
        
        IEEE floating point standard 754
    - - Primary data type in business data processing like COBOL
      - Data stored
        
        Using binary coded decimal
        
        As integers with decimal being attribute(scala factor)
      - Store fixed number of decimal digits with fixed position for decimal points
      - Advantages
        
        Precisely store decimal values
      - Hardware support is available but may be software simulated
      - Disadvantages
        
        stored similar to character strings
        
        More storage taken than binary
        
        Restricted range(no exponents)
    - - Numbers are code points
      - Single character as value
      - Character set is aggregate of all characters
      - Stored as numeric codes
      - Assignment of numbers are code pages
      - Ordering is collating sequence
      - Each character assigned to different number
      - Commonly used
        
        Unicode
        
        ISO 8859-1
        
        8-bit ASCII
      - most language include primitive type for single character except python
    - - About
        
        Also known as Logical data type
        
        Represents True & False
        
        Used to implement a choice
      - Value Representation
        
        Denote True by 1, False by 0 & any other value by -1
        
        Follows Boolean algebra
        
        Provision is made by language for collection of bits
        
        Can have either true or false
      - History
        
        Simplest data type
        
        Improves readability
        
        Introduced in ALGOL 60
        
        C89 uses numerical expressions as conditionals
    - - Language support (Fortran & Python)
        
        Represented as ordered pairs of floating pounts
        
        Explicitly specified in python
        
        Allows arithmetic
      - Symbol table
        
        Information about
        
        Type
        
        Scope level
        
        Declaration or presence in source code
        
        Employed by language translator
      - Descriptors
        
        used by run-time system if dynamic
        
        Collection of attributes of variables
        
        Used for type checking and building code
        
        Required only at compile time if static
  - - - Ordered list of distinct values
        
        Advantages
        
        Readability
        
        Reliability
        
        Basic operations
        
        Assignment
        
        Successor / Predecessor
        
        Relational operators
    - - define new names for possibly restricted or constrained versions of existing types
      - Subrange types are inbuilt in some languages
        
        C language does not support
        
        Pascal do support
- - - - Operations modelled by function
      - Test modelled by
        
        Relations on the sets
        
        Functions on the sets
      - Data sorted into sets
    - - Available types of operations
      - Provided mechanisms
        
        Storing data
        
        Controlling operation sequence
      - Allowed data type
  - - - Similar motivation to Process abstraction
      - Can declare variables while hiding the type
      - Unnecessary details pf type can be hide
      - Include subprograms that provide the operations for that type
    - - Allows to collect instances of entities
      - Common attributes need not be considered
      - View representation of an entity
    - - Process Abstraction
        
        Provide a way for a program to specify a process
        
        Not provide the details of how it perform a task
      - Data Abstraction
        
        Includes
        
        the data representation of one specific data type
        
        the subprograms that provide the operations for that type
  - - - Allow programmers to specify accuracy
      - Structured data type for information record
    - - Accuracy specification for int & float
      - Many data types with greater support
    - - Linked list & bunary tree implemented with arrays
    - - Few basic types
      - Few flexible structure defining operators
- - - - Selection of correct operations when overloaded
      - Storage management
        
        Size of data block
        
        Allocation
        
        Lifetime
      - Storage representation
        
        Attribute representation
        
        Preferred location
        
        Register
        
        Stack
        
        Heap
        
        Bit representation
      - Static type checking
  - - - Hardware provided
        
        Inbuilt
        
        Other developers
        
        Standard libraries
      - Programmer constructed
        
        Functions & library routines
        
        In-line code sequences
      - Language provided
        
        Int
    - - Data Structures (Arrays, Records)
        
        Data object aggregation
        
        Variable memory space for values
        
        Building blocks are components
        
        Built with other data types
      - Elementary Data Objects (Integer, Boolean, Character)
        
        Not defined in terms of other types
        
        Usually an ordered set with min & max
        
        Always manipulates as a unit
        
        Values stored in fixed memory spaces