C++ Pointers and References Clarification -

this me understand pointers better, if guys can confirm/deny/explain looks don't understand appreciative. examples of using mailboxes, , aunts, , streets, , crap confusing.

int = 5;  int b = &a; // b memory address of 'a'  int *c = a; // c value of 'a' 5  int *d = &a; // d pointer memory address of 'a'  int &e = a; // be?   void functiona() {      int = 20;      functionb(&a);      // 15? }  void functionb(int *a) {      = 15; } 

thank guys help, trying improve understanding beyond of crappy metaphor explanations im reading.

i'll take things 1 one:

int b = &a; // b memory address of 'a' 

no. compiler (probably) won't allow this. you've defined b int, &a address of int, initialization won't work.

int *c = a; 

no -- same problem, in reverse. you've defined c pointer int, you're trying initialize value of int.

int *d = &a; 

yes -- you've defined d pointer int, , you're assigning address of int -- that's fine. address of int (or array of ints) pointer int holds.

int &e = a; 

this defines e reference int , initializes reference a. it's legitimate, not useful. reference, common use of reference function parameter (though there other purposes, of course).

void functiona() { int = 20; functionb(&a); } void functionb(int *a) { = 15; } 

to make work, need change assignment in functionb:

void functionb(int *a) { *a = 15; } 

as was, trying assign int pointer, won't work. need assign int int pointer points at change value in calling function.