Chapter 4: How do I write programs?

Question 1

Instruction set

Answer 1

Set of basic commands or instructions that a processor can understand directly

Question 2

Machine code

Answer 2

Instructions that can run directly on a computer’s processor

Question 3

Program

Answer 3

Set of instructions written to perform specific tasks on a computer

Question 4

Programming language

Answer 4

Language designed for humans to communicate instructions to computers

Question 5

Source code

Answer 5

Instructions written in a programming language that both humans and computers can understand

Question 6

Syntax

Answer 6

Rules that determine how the words and symbols in a valid instruction are arranged

Question 7

Syntax error

Answer 7

Result of incorrect source code that causes the translation process from source code to machine code to fail

Question 8

Compiler

Answer 8

• Code translator program that translate source code to machine code completely before running the program
• Advantages:
  
  • Resulting program runs at faster speed as all
    translation done beforehand
  • Compiler is not needed to run the program after
    compilation is completed
  • Syntax errors are detected before the program even
    runs
• Disadvantages
  
  • Any changes to the source code require
    recompilation before taking effect
  • Compilers usually do not offer an interactive mode

Question 9

Interpreter

Answer 9

• Code translator program that translates source code to machine code while the interpreted program is running
• Advantages:
  
  • Changes to the source code take effect immediately
  • Interpreters usually have an interactive mode that
    facilitates learning and experimentation
• Disadvantages:
  
  • The resulting program runs at a slower speed
    because translation occurs when the program is
    running
  • Needs to be run every time the program is started
  • Syntax errors may interrupt the running of the
    program