Software development languages

Machine Code

Machine code is the only code that the processor understands and is:

• Written in 1s and 0s (binary)
• Very hard for humans to understand
• Very hard to spot mistakes and to make changes
• Specific to a processor

High Level Language

Most programmers will use a high level language to write their code because they are:

• Written in English-like language
• Easy to learn
• Easy to understand, make changes and spot mistakes
• Can be transferred between different types of computer
• BUT processors do not understand high level languages

To solve the problem of processors not understanding high level languages, a program called a translator is used.

Translators

A translator is used to convert a high level language into machine code (low level language).

There are two types of translator:

• Interpreter
• Compiler

• Interpreter

  • Translates one line at a time
  • Gives accurate error messages where the error occurs
  • Easier to spot/edit mistakes
  • BUT every time code is run you must use the interpreter

  Compiler

  • Compiles whole code in one go therefore faster than interpreter
  • Only needs to be compiled once and produces object code
  • Can be harder to spot/edit mistakes

  Interpreter v Compiler

  An interpreter is used for program development as it is easier to debug and partially test the code. Once the program is error free and complete, the program should then be compiled, as compiling only needs to be done once.