Creating Software

Creating Software

1. High-Level Language

   • Python, JavaScript, C, C++
   • One instruction of high-level code (requires a lot of abstraction), represents many instructions of machine code.
   • The same code works for many processors and machines
   • Programmers can easily store data in different types of structures (eg. list and arrays) without knowing about the memory structure
   • Code is easy to read, understand and modify
   • Must be translated into machine code before computer can understand.
   • Don't have much control over what the CPU does so programs will be less efficient and slower.

2. Low-Level Language

   • One instruction of assembly code usually only represents one instruction of machine code
   • Usually written for one type of machine or processor and won't work on others.
   • Machine Code, Assembly Code
   • Programmer needs to know about the internal structure of the CPU and how it manages memory.
   • Code is very difficult to read, understand and modify.
   • Commands in machine code can be directly processed without a translator.
   • Programmer controls what the CPU does and how it uses memory so programs will be more efficient and faster.

3. Translators

   • Compiler
     • Translates all of the code at the same time and creates one executable file.
     • Only needed once to create the executable file.
     • Returns a list of errors for the entire program once compiling is complete.
     • Once compiled the program runs quickly, but compiling can take a long time.
   • Assembler
     • Turns assembly code into machine code
   • Interpreter
     • Translates and runs the source code one instruction at a time, but doesn't create an executable file.
     • Needed every time you want to run the program.
     • The interpreter will return the first error it finds and then stop, which is useful for debugging.
     • Programs will run more slowly because the code is being translated as the program is running.

4. Integrated Development Envirnoment

   • TREE
     • Translators
       • When you run code, it will be used to translate high level code to low level code.
     • Run Time Environmnet
       • Allows you to run code quickly so you can see that it works- iterative testing (used when you're developing the program).
     • Editor
       • Colour codes command words, auto intend code, sometimes autocomplete code as you type it.
     • Error Diagnostics (Debugging tools)
       • Used to debug code, locates errors and suggests ways to fix them.