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Introduction, Regular Expressions - Coggle Diagram

- - - - What
        
        A logical data type which uses true and false
      - why
        
        Numeric expressions can be evaluated as boolean data
        
        Used to control programming structures that allow us to implement selection into our programs
      - Value Representation
        
        A single bit can be used but instead an addressable unit like byte is used
    - - Character Set
        
        A collection of characters that are used in a computer system or programming language
      - What
        
        A single character as its value store in computer as numeric codes(8BIT ascii and ISO) . In the Current days we have unicode to encode characters as numeric codes
        
        Unicode
        
        A 16 bit character set which allows to store characters of different languages
    - - Integer
        
        Operations on Integer Data
        
        Unary Operations
        
        Relation Operations
        
        Binary Operations with signature
        
        Arithmetic Operations
        
        Representation
        
        Computer
        
        As a group of Binary Digits
        
        Real World Representation
        
        Whole Numbers which can be used in the real world and in addition in programming to control flow of the programs efficiently
        
        Storage Representation
        
        Signed
        
        One's Compliment
        
        Two's Compliment
        
        Sign Magnitude
        
        Unsigned
        
        Operations on Integer Data
        
        Difference between Integer Data Types
        
        Language-Dependent
        
        May or may not be allowed to contain negative values.
        
        Machine Dependdency
      - Hardware support
        
        Supported by programming languages i.e -Python
        
        Supported By hardware
      - Floating Point Numbers
        
        Computer Representation
        
        IEEE Floating-Point Standard 754 Format
        
        Base
        
        Exponent
        
        Mantissa
        
        Real World Representation
        
        As Real Numbers
        
        Issues in Floating Point numbers
        
        Some floating point numbers cannot be represented with binary data
        
        Loss of Accuracy through mathematical operations
        
        The fault in approximating the real values
      - Floating Point Data Type
        
        What
        
        Stored as String types
      - Decimal Type
        
        What
        
        Decimal data types store a fixed number of decimal digits, with the decimal point at a fixed position in the value.
        
        Moat business application supportive computers gives hardware support for decimal data types
        
        Advantages of Decimal Data Types
        
        It allows us to store decimal values precisely within a given range
        
        Disadvantages of Decimal Data Types
        
        The range of values are always limited
        
        Memory wasteful representation in the computer
        
        This inefficiency in memory can be insignificant if there is a large number of decimal values to be stored
        
        Real Numbers whci are very small cannot be distinguished by the fixed point real number representations
        
        Not accurate enough to built scientific and technological applications
        
        Representation in the Machine
        
        Digits are stored as Binary Coded decimals
        
        Decimal point is not stored with the value
        
        Decimal values are stored as integers
        
        Decimal point becomes an attribute of the data
      - Complex Numbers
        
        Some Programming Languages support Complex Data types
        
        This numbers are represented as ordered pairs of floating point values
        
        Supportive Languages also provide the relevant operations
    - - Values consist of sequence of characters.
      - Design Issues
        
        Primitive or not?
        
        Pacal,c,pp as non-primitive where as python consider as primitive
        
        Length is Static or Dynamic
        
        In C the string is terminated by a null character
      - Types of String Length
        
        Static
        
        The length can be static and set when the string is created.
        
        Dynamic
        
        Allow strings to have varying length with no maximum
        
        Limited dynamic length strings
        
        Allow strings to have varying length up to a declared and fixed maximum set by the variable’s definition
      - Descriptor of a Character String
        
        Descriptor for a staticc character string type
        
        type's length
        
        name of the type
        
        the address of the first character
        
        descriptor for a limited dynamic character string type
        
        fixed maximum length
        
        current length
        
        Limited dynamic strings in C or C++ doesnt requrie runtime descriptors because of the ending of each string with a null cahracter
        
        descriptor for a limited dynamic character string type
        
        Only the current length of the string
        
        Needs more complex memory management
      - Common String operations
        
        Assignment
        
        Comparison
        
        Concatenation
        
        Substring Selection
        
        Pattern Mathcing
      - Evaluation as array or priimtiive
        
        Dealing with strings as arrays can be more cumbersome than dealing with a primitive string type.
        
        It is just to consider strings as primitive in the modern era
        
        JAVA
        
        String are classes
        
        StringBuffer
        
        String
        
        Immutable
        
        PYTHON
        
        Consider strings as primitives and has operations defined as well
        
        Immutable
  - - - Maintained during the runtime by the system
    - - Required only at compile time thus build by the compiler in the compiler time
- - - - An enumeration is an ordered list of distinct values which is used to assign
        names to integral constants since names are easier to handle in program.
      - The programmer defines both the literal names to be used for the values and
        their ordering in a declaration
    - - Are enumeration values coerced to integer?
      - Is a literal constant allowed to appear in more than one type definition.
    - - Relational Operations
      - Assignment
      - operations such as successor and predecessor
    - - Simulate them with integers
    - - Readabiulity
      - Reliability
  - - - Contiguous subsequence of an ordinal type
      - Define new names possibly restricted existing types
      - All the valid operations in the previously as well .
    - - Implemented by using a non-negative value in the symbolic constant