What exactly are C++ definitions, declarations and assignments?

by

A definition is where a value or function is described, i.e. the compiler or programmer is told precisely what it is, e.g.

int foo()
{
  return 1;
}

int var; // or, e.g. int var = 5; but this is clearer.

A declaration tells the compiler, or programmer that the function or variable exists. e.g.

int foo();
extern int var;

An assignment is when a variable has its value set, usually with the = operator. e.g.

a = b;
a = foo();

More Related Contents:

  1. Initialization of all elements of an array to one default value in C++?
  2. What can I do with a moved-from object?
  3. Why do C and C++ support memberwise assignment of arrays within structs, but not generally?
  4. The differences between initialize, define, declare a variable
  5. Why are two different concepts both called “heap”? [duplicate]
  6. Copy constructor and = operator overload in C++: is a common function possible?
  7. What exactly do “IB” and “UB” mean?
  8. Why does C++ allow an integer to be assigned to a string?
  9. Global scope vs global namespace
  10. Why is `i = ++i + 1` unspecified behavior?
  11. What exactly is the difference between “pass by reference” in C and in C++?
  12. What distinguishes the declaration, the definition and the initialization of a variable?
  13. What is an opaque value in C++?
  14. What is half open range and off the end value
  15. What does “Memory allocated at compile time” really mean?
  16. Why C/C++ is slower than Assembly and other low level languages?
  17. Save Current Date into 3 Ints – C++ [closed]
  18. C++ Taylor series
  19. Why should one not derive from c++ std string class?
  20. Where is Boost.Process?
  21. How define an array of function pointers in C
  22. Function pointer as parameter
  23. Why is my object not being copied when move constructor is deleted?
  24. C++ abstract class without pure virtual functions?
  25. Why in the code “456”+1, output is “56” [duplicate]
  26. How to write `is_complete` template?
  27. Pseudo-destructor call does not destroy an object
  28. Class template for numeric types
  29. C++ class with template member variable
  30. How to add WTL and ATL to visual studio c++ express 2008

Leave a Comment