[C++] new & new(nothrow)

If there are not enough memory when new some data in C++, it will have a exception.

Do something like this:

long long n = 1LL << 63LL;
int *p = new int[n];

Then you will get a exception like this:

libc++abi.dylib: terminating with uncaught exception of type std::bad_alloc: std::bad_alloc

But if you use the new(nothrow), instead of exception, you will get a null pointer.

long long n = 1LL << 63LL;
int *p = new(nothrow) int[n];
if (p == nullptr) cout << "Null Pointer" << endl;

Output:

Null Pointer