Declaring array of int

Question

Is there any difference between these two declarations?

int x[10];

vs.

int* x = new int[10];

I suppose th

Answer 1

The only thing similar between

int x[10];

and

int* x = new int[10];

is that either can be used in some contexts where a int* is expected:

int* b = x;   // Either form of x will work

void foo(int* p) {}

foo(x);      // Either form will work

However, they cannot be used in all contexts where a int* is expected. Specifically,

delete [] x;  // UB for the first case, necessary for the second case.

Some of the core differences have been explained in the other answers. The other core differences are:

Difference 1

sizeof(x) == sizeof(int)*10   // First case

sizeof(x) == sizeof(int*)     // Second case.

Difference 2

Type of &x is int (*)[10] in the first case

Type of &x is int** in the second case

Difference 3

Given function

void foo(int (&arr)[10]) { }

you can call it using the first x not the second x.

foo(x);     // OK for first case, not OK for second case.