My Interpretation of Pointers & References

Way back early in the tutorials I read the c++ tutorials page on pointers and references which helped me coming into this.

int val1 = 1;
int val2 = 2;
int val3 = 3;
int* valPtr = &val1;
int& valRef = val2;

I’ve changed it up and added another value while also pointing the reference to val2.

So at first in the order of Val1, Val2, Val3, valPtr, valRef my output would be:


The address would be:

(Add_A, Add_B, Add_C, Add_A, Add_B)

Now I can change the value of val3 in 1 of two ways. I could assign the memory address a new value, or I could change the memory address that val3 is stored.

val3 = *valPtr;

The should change val3 to (1, Add_C). It’s kept the same memory address but changed the value within it. testing this returns true.

Now I can change it the other way.

&val3 = valPtr;

this should chane val3 to (1, Add_A). It hasn’t copied the value, it’s changed it’s memory address. Whoops this doesn’t work! Compile error!


valPtr = &val3;

this returns valPtr as (3, Add_C). I have changed the ADDRESS the pointer is referring to, however have left the value in its original address untouched.

So it seems you can assign a value to the value of a pointer. However you cannot assign the address of a value to the address of the pointer.

You can assign the Address of the pointer to the address of the value however. I suppose this makes sense. You can’t just be shifting the value address, what if the address it is moving to already has a value? PROBLEMS!

Now for references let’s try the same thing. Let’s first try and change the value while maintaining the address.

valRef = val3;

this returns valRef as (3, Add_B). Success! we have reassigned the value in memory address Add_B using a reference.

now let’s try to change the ADDRESS valRef is reffering to.

&valRef = &val3;

Compile error “expression must be a modifiable lvalue” So much like the actual value, the reference address cannot be changed >=(

okay lets try break something.

std::string Address = "";
Address = &val3
std:cout << Address;

Oh well too ambitious. Well instead of writing:

*valPtr = val3;

we instead wrote

*valPtr = &val3

we would be storing Add_C into the value of Add_A. Which obviously doesn’t work! that’s why I was trying to store it into a string but c++ can not just convert 012FB048 to a string so easily.

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