C++ Pointers Backup

Front 1

int i = 2;
int j = ++i;
j++;
cout << i << " ";
cout << j << " ";
cout << (&i == &j) << endl;

Back 1

3 4 false

Front 2

int i = 2;
int& j = ++i;
j++;
cout << i << " ";
cout << j << " ";
cout << (&i == &j) << endl;

Back 2

4 4 true

Front 3

const int a[] = {2,3,4}

creates an array where in C++

Back 3

stack

Front 4

final int[] a = {2,3,4}

creates what on where in Java

Back 4

reference, heap

Front 5

final int[] a = {2,3,4}

changing possible?

Back 5

reference to array in Java is immutable, but array contents are mutable

Front 6

const int a[] = {2,3,4}

changing possible?

Back 6

yes. would change actual array

Front 7

int i = 2
int& j = ++i
does what

Back 7

reference ties j to i (so changing j changes i)

Front 8

Object's equals() compares ..., not ...

Back 8

references, not contents

Front 9

C++ const vars must be ... when declared

Back 9

initialized

Front 10

type*, e.g. int*

means

Back 10

reads as pointer to an int and denotes the address of the var which is of type int

Front 11

*variable, e.g. *p

Back 11

p is an int* and reads "value at address". So ++p means incrementing the pointer (or address), whereas ++*p means incrementing the value at the address (stored by p) by 1.

Front 12

type&, e.g. int& j = ++i

Back 12

this should be read as the "address of an int stored in j has been assigned the incremented value of i", which means i and j are now tied forever so whenever i changes, j changes to match it and vice versa. This also means j is another name for i and cannot be assigned to another value later (I think) and you also can't increment j like ++*j since j isn't an address. It'd the equivalent of saying ++*i which doesn't make sense. If you print both of i and j's address in memory, they both have the same address.

Front 13

variable&, e.g. int* p = &j,

Back 13

says that the "address of" j is stored in a pointer to an int and that pointer is called p in this case.

Front 14

void g(int* p){ ++p;}

int main () {
int j = 3;
g(&j);
cout << j }

prints what

Back 14

3

Front 15

void g(int* p){ ++*p;}

int main () {
int j = 3;
g(&j);
cout << j }

prints what

Back 15

4

Front 16

void g(int& p){ ++p;}

int main () {
int j = 4;
g(j);
cout << j }

prints what

Back 16

5

Front 17

void h(int& r) is a method whose argument demands a ... that cannot be ...

Back 17

l-value that cannot be 0 since it's a null address