int`* p = new int [5];和int * p = new int [5];之间有什么区别？

Question

I just need to understand what the differences between these are:

int *p = new int[5];

and

int *p = new int(5);

Answer 1

One creates an array of five int s and assigns a pointer to this array's first element to p . None of the integers in this array are initialized:

int *p = new int[5]; // a pointer to an array of 5 integers

The other one creates a single int , and assigns a pointer to that int to p . This integer is initialized with 5 :

int *p = new int(5); // a pointer to an int

As tadman points out in his comment, in essence, the difference is between the operator new and operator new[] . new[] allocates an array and must be deleted with delete[] , while new allocates a single object and must be deleted with delete . If you delete with the wrong operator, what happens is undefined behavior. Of course, unless you are a library implementer, you should generally prefer smart pointers and library containers over new and new[] .