Compsci Test 1

Chapter 1

  • Hardware
    • Input Output typical hardware devices
    • Input 
      • Data that the computer collects from people and other devices
      • Input device 
      • Component that collects the data
        • Keyboard, Mouse, Touchscreen, scanner, camera
        • Disk drives can be considered input devices because they load programs into the main memory
    • Output
      • Data produced by teh computer for people and devices
      • Text, Image, Audio, or bit stream
        • Output device
        • Formats and presents output
          • Video Display, Printer
          • Disk drives and USB, because data is send to them
    • Central Processing Unit (CPU)
    • The part of the computer that actually runs the program
    • Software cannot run without it
    • Used to be big
    • Microprocessors
      • CPUs on small chips
    • Main memory (RAM)
    • Where the computer stores a program while the program is running, and data used by the program
    • RAM
      • CPU is able to access data in RAM
      • Contents are erased when the computer is off
    • Secondary Storage devices
    • Can hold data for a long time
    • Programs are stored here and loaded to main memory when needed
    • Types
      • Diskdrive
      • Solidstate drive
      • Flash memory
  • Software
    • Application Software
    • Programs that make computer useful for everyday tasks
      • Email, Games, Webbrowser
    • System Softwaree
    • Programs that control and manage basic operations of a computer
      • Operating system
      • Utility Program
      • Software Development tools
  • CPU Cycle
    • Fetch decode execute
    • Fetch: Read the next instruction from memory into cpu
    • Decode: CPU decodes fetched instruction to determine which operation to perform
    • Execute: Perform the operation
  • Binary
    • Byte
    • Just enough memory to sore letter or small number
    • Divided into eight bits
      • Electrical component that can hold positive or negative charge, like an on or off switch
  • Compiler
    • Translates high level language into program language
  • Interperter
    • Translates and executes instructions in high-level language programs
    • Used in python
    • Interprets one instruction at a time

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Chapter 2

  • Input / Output
    • Computer performs three step processes
    • Recive Input
    • Perform process on it
    • Produce Output
  • General Functions
    • Function
    • Piece of prewritten code that performs and operation
    • Print
    • Displays output on the screen
    • Input function
    • Variable = input(prompt)
    • Always returns as a string
  • String
    • Characters used as data
    • Enclosed in “”
    • \
  • Variables
    • Assign variables
    • Variable = expression
      • Ex: age = 29
    • Naming rules
    • Cant be a keyword
    • No spaces
    • First character must be a letter or underscore
    • Can use letters digits or underscores
    • Case sensitive
    • Reassignments and data types
    • Garbage collection removes values that are no longer referenced
    • Int
    • No decimal point
    • int(item) converts and item into and int
    • Float
    • Decimal point
    • float(item) converts and item into a float
    • Convert
  • Comments
    • Notes of explanation
    • Start with #
  • Math Expressions
    • Modulus
    • Division
    • / floating point division
    • // integer division
    • Exponentation (exponent)
    • (**)
    • Multiplication
    • (*)
    • Remainder
    • (%)
    • Addition
    • (+)
    • Subtraction
    • (-)
    • Higher precedence performed first
    • Same precedence is left to right

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Chapter 3 

  • Python Syntax
  • If statement
    • If condition is not true it just exits the structure
    • If condition:

Statement

Statement

  • If Else
    • Understand flowchart
    • If condition :

Statements

Else:

 Other staments

  • If Elif Else

    • Syntax
    • Multiple if else statements
    • Check first condition, if its true, check the second condition
    • You can include multiple statements, not just two
    • Look a the flow chart

  • Boolean

    • Greater than less than
    • == determines wether two operands are equal to each other
    • ! = determines wether the two operands are not equal
    • \
    • True or false

  • Nested Expressions

  • Logical operators

  • Compare strings