pointer decleration

[globalenemy]

Greetings,

I'm wondering about how to declacre my stuff.
on my journey into c++, the internet has shown me theese:

SomeType type;
SomeType* type;
SomeType *type;
SomeType** type;

Especially 2 and 3 freak me out. Could someone explain this to me? what do each of theese declerations mean and what does it mean for cleaning up theese types?

[S G H]

They are the same (Pointer to SomeType)
I wonder how doesn't 4 freak you out, since it's a Pointer to Pointer to SomeType.


Think of a chocolate bar.

// Say this chocolate bar is made of 8 pieces
ChocolatePiece A[8];
ChocolatePiece* B;

Your chocolate bar looks like this:
[ ][ ][ ][ ][ ][ ][ ][ ]
This is what A looks like right now.


Now, look at your finger.
Make it point at one piece of your chocolate bar.
[ ][ ][X][ ][ ][ ][ ][ ]

 // Take the address ("location", "position") of A's third item
B = &A[3];

This is what B is meant for: Pointing to an item.

Your finger can touch (read) what it's pointing at:

// The same as myFingerPointsTo = A[3];
ChocolatePiece myFingerPointsTo = *B;

Also your finger can smash (change) what it's pointing at:

// Now A[3] is WhiteChocolate.
*B = WhiteChocolate;

A pointer to a pointer... is just like a finger, pointing to a finger, pointing to a chocolate piece.


The only "unusual" tokens you'll have to remember with pointers are * and & .

When declaring a type, using * means this type is a pointer:
int* a; // a is a pointer-to-int
When declaring a type, using & means this type is a reference:
int& b = c; // a is a reference-to-int. Must be initialized.
When using variables, using * means you want to read what a pointer is pointing to.
int d = *a;
When using variables, using & means you want to get a pointer to this item.
int* e = &d;

References are slightly different pointers. You can think of them as variable aliases.

int a=0;
int& b=a;
// a and b are the same. Only their name differs. 

[globalenemy]

Thank you. this helps. Still a bit confused about this stuff, but i'm getting there.