Int ** a [3] [4] and sizeof (a) and int (**) a [3] [4]

BS makes it clear in C ++ programming that the variable name is more binding than the previous one.

Therefore, the following Variable declaration:
Int ** a [3] [4];
The two-dimensional array "[]" of the "int ** type is more binding than" int "and ). This two-dimensional array has a total of 12 members (3 × 4), each member is a pointer int **), and each pointer is 4. If it is a 32-bit computer, other computers ). Therefore, the length of this array is 12 × 4 = 48.

A is an array, not a pointer

Sizeof (a) = sizeof (int **) * 3*4

A is an array, So If sizeof (a) is used to calculate the value, it should be sizeof (int **) * 3*4 = 48

If a is passed to the function as a parameter, it is automatically degraded to an int ** pointer.

Fun (int ** a, int row, int col );
Use sizeof (a) in the function to measure 4 = sizeof (int **)

I think the basic type of a is int **, And the size is naturally 4. [3] [4] has 12 elements. 4*12 is 48.
64-bit machines must be doubled (because the pointer length of 64-bit machines is 4*2 = 8 bytes)

In this example, a is not a pointer, but an array name.
The array name has two internal meanings:
1. The first address of the array. If you define a pointer to the array, it means it)
2. Array occupies the size of type * Number
So when you
Int m_ia [4];
Int * p = m_ia;
Sizeof (m_ia) = 4 * sizeof (int)
Sizeof (p) = 4

The first thing to note
Int ** a [3] [4]
Defines a set of two-dimensional pointer arrays pointing to pointer variables,
That is to say, a pointer array with three rows and four columns is defined. Each Pointer Points to a pointer,
In terms of storage structure, it is an array that stores 12 pointer variables,
The question is, "How many bytes does a occupy ?"
What does a mean here,
The actual meaning of a is an address, indicating the first address of the array a [3] [4,
As an address, a occupies 4 bytes;
A is also a representation of the array a [3] [4,
If sizeof (a) is used to solve the problem, it represents the space occupied by the array a [3] [4,
Instead of the storage space occupied by address,
That is, the space occupied by 12 pointer variables is naturally 48 bytes.
This statement is correct. Here a refers to the array a [3] [4], but if:
Int a [3] [4];
Int * p = & (* a [3] [4]);
Cout <sizeof (p );
Result 4

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