I want to follow up on this question: What is the difference between a definition and a declaration?, there is answer about definition and a declaration, but nothing about implementation.
I want also know what is the difference between implementation and definition.
2 Answers
implementation: if you have some pseudo-code or something like an UML-Diagram and write your code on that basis it's an implementation
declaration: a declaration is already in your code where you say the compiler/interpreter: "hey look there is this variable that I want to use but I dont want to give it any value yet"
and finally definition: definition is when you finally assign a value to your variable like x = 4. Like your defining x to be 4 (in your code)
Hope this is helpful to you
Function definition etc is a formal term, but "implementation" is a fuzzy informal term. In plain English, it could refer to your application's implementation of something, like for example a function. The implementation phase of a project is typically the phase where you write all the code. And so on - it depends on context.
In formal/technical C programming terms, implementation means the implementation of the C language. That is: formally implementation means the C compiler and standard library. And the formal term implementation-defined behavior means compiler-specific behavior.
