方法一(使用new)

Method 1 (using new)

• 为免费存储上的对象分配内存(这通常与堆相同)
• 要求您稍后明确删除您的对象.(如果你不删除它，你可能会造成内存泄漏)
• 内存保持分配状态，直到您删除它.(即您可以返回一个您使用new创建的对象)
• 问题中的示例将泄漏内存，除非指针是delete代码>d;并且它应该总是被删除，无论采用哪个控制路径，或者是否抛出异常.

• Allocates memory for the object on the free store (This is frequently the same thing as the heap)
• Requires you to explicitly delete your object later. (If you don't delete it, you could create a memory leak)
• Memory stays allocated until you delete it. (i.e. you could return an object that you created using new)
• The example in the question will leak memory unless the pointer is deleted; and it should always be deleted, regardless of which control path is taken, or if exceptions are thrown.

方法二(不使用new)

Method 2 (not using new)

• 为堆栈上的对象分配内存(所有局部变量所在的位置) 堆栈可用的内存通常较少；如果分配的对象过多，则会面临堆栈溢出的风险.
• 您以后无需删除它.
• 超出范围时不再分配内存.(即，您不应该return 指向堆栈上的对象的指针)

• Allocates memory for the object on the stack (where all local variables go) There is generally less memory available for the stack; if you allocate too many objects, you risk stack overflow.
• You won't need to delete it later.
• Memory is no longer allocated when it goes out of scope. (i.e. you shouldn't return a pointer to an object on the stack)

至于使用哪个；考虑到上述限制，您可以选择最适合您的方法.

As far as which one to use; you choose the method that works best for you, given the above constraints.

一些简单的案例:

• 如果您不想担心调用 delete，(以及可能导致 内存泄漏) 你不应该使用 new.
• 如果你想从一个函数返回一个指向你的对象的指针，你必须使用 new

• If you don't want to worry about calling delete, (and the potential to cause memory leaks) you shouldn't use new.
• If you'd like to return a pointer to your object from a function, you must use new