CCC101

• Computer ‣ an electronic, programmable device that can store, retrieve, and manipulate data
• Major components of a computer: Hardware and software
• Hardware ‣ tangible part of the computer

  ‣ composed of electronic and mechanical parts
• Software ‣ intangible part of the computer

  ‣ consists data and computer programs
• Hardware - Main Memory, Secondary Memory, Central Processing Unit, Input Devices, Output Devices
• Memory ‣ where data and instructions needed by the CPU to perform are stored
• Main Memory ‣ used to hold programs and data that the processor is actively working on
• Secondary Memory ‣ used to hold programs and data for long term use
• Memory Cell ‣ an individual storage location in the memory
• Address of a memory cell ‣ the relative position of a memory cell in the computer’s main memory
• Contents of a memory cell ‣ the information stored in a memory cell, either a program instruction or data
• Bit ‣ smallest element a computer can deal with
• Byte ‣ the amount of storage required to store a single character

  ‣ there are 8 bits to a byte
• Central Processing Unit (CPU) ‣ coordinate all computer operations
• The CPU continuously do: fetch - decode - execute
• How does one declare a function in C? - via a function prototype
• I/O Devices ‣ allows a computer system to interact with the outside world by moving data in and out of the system
• Input Device ‣ peripheral devices used to enter information for computation
• Examples of input devices: keyboard, mice, microphone
• Output Device ‣ peripheral devices that receives data from the computer used for observing the results of computation
• Examples of output devices: monitor, printer, speaker
• Software ‣ programs used by a computer to operate
• Program ‣ collection of instructions that makes a computer perform a specific task when executed

  ‣ list of instructions that tell a computer what to do
• Applications Software ‣ programs that assist a computer user in accomplishing specific tasks e.g. Microsoft Word, Google Chrome, Steam
• Systems Software ‣ programs that are needed to keep all the hardware and applications software running together smoothly

  ‣ interface between the hardware and the user applications e.g. Operating systems like Windows, Linux, MacOS
• Compiler ‣ translates a high-level computer program into machine language
• Machine Language ‣ language directly understood by a computer

  ‣ collection of binary numbers understood by a specific CPU
• Programming Language ‣ standardized communication technique for expressing instructions to a computer
• Assembly Language ‣ mnemonic codes that correspond to machine language instructions

  ‣ computer operations are represented by mnemonic codes rather than binary numbers and variables can be given names rather than binary memory addresses
• High-level Language ‣ used to write programs that are independent of the CPU on which they will be executed

  ‣ combine algebraic expressions and English symbols

  ‣ is not directly understood by a computer
• Syntax ‣ rules of a specific programming language

  ‣ it defines how we can put together symbols, reserved words and identifiers to make a valid program
• Semantics ‣ refers to the meaning of a program statement and its purpose and role in a program
• A program that is syntactically correct is NOT necessarily semantically correct
• Steps in Software Development Method

  1. Problem Definition
  2. Problem Analysis
  3. Algorithm Design and Representation
  4. Coding and Debugging
• Problem Definition - computer programming requires us to define the problem first before we even try to create a solution
• Problem Analysis ‣ involves breaking up the problem into smaller and simpler sub-problems
• Algorithm ‣ list of steps for solving a problem

  ‣ a clear unambiguous specification of the steps needed to solve a problem

  ‣ is a well-ordered collection of unambiguous and effectively computable operations that, when executed, produces a result and halts in a finite amount of time
• Syntax Error / Compile-time Error ‣ occur if there is syntax error in the code
• Runtime Errors ‣ occurs when the program directs the computer to perform an illegal operation e.g division by zero
• Logic Error ‣ caused by following an incorrect/faulty algorithm