C + + Primer Dynamic array of notes in the 12th chapter

New and array

In order for new to assign an array of objects, you must follow the type name followed by []. The number of allocations specified therein;

int New int [Get_size ()]; // [] must be an integral type, but not necessarily a constant;  int arrt[]; int New ARRT; // assigns an array of 24 int, p points to the first int;

Initialization, c++11: Available curly braces {};

It is legal to allocate an empty array dynamically;

To release a dynamic array:

Delete p; Delete []  PA;

Smart pointers vs. dynamic arrays:

The standard library provides a unique_ptr version of an array that can manage new allocations

You must add an empty [] after the type;

// Up points to an array containing 10 uninitialized integers; unique_ptr<int[]> up (newint  [ten]); Up.release ();     // Automatic delete[], destroying its pointer;

Note: The up pointer is an int array, not an int, and the point or arrow member operator cannot be used;

However, you can use the subscript operator to access the elements in the array;

 for (size_t i =0; i!=; + +i) {        = i;}

SHARED_PTR does not support managing dynamic arrays

SHARED_PTR does not define subscript operators, and the smart pointer type does not support pointer arithmetic operations;

If you use it, you must define your own delete;

shared_ptr<int> SP (  newint[ten], [] (intDelete  []p;} ); Sp.reset (); // use a custom lambda to release the array, which uses delete[];

C + + Primer Dynamic array of notes in the 12th chapter