C + + Two-dimensional array delivery

C + + Two-dimensional array delivery

When we pass a two-dimensional array, there may be some problems for the novice, and here are some of the delivery methods

When explaining how to pass a two-dimensional array, first look at how dynamic new two-dimensional arrays

1 //Dynamic application of two-dimensional array2     intRow, col;3CIN >> Row >>Col;4     5     int**arr;6     //C + + form7arr =New int*[row];8      for(inti =0; i<row;i++)9Arr[i] =New int[col];Ten      One     //C Form AArr = (int**)malloc(sizeof(int*) *row); -      for(inti =0; i<row;i++) -Arr[i] = (int*)malloc(sizeof(int) * col);

This method defines a level two pointer, and a level two pointer to an array element that is an integer pointer. And then the new array of the shaping pointer, so that the two-dimensional array is dynamic new.

Here is how to see the type of a variable, in C + +, by including the #include<typeinfo> header file, it is easy to print out the variable type, the following statement:

cout << typeid (variable_name) << Endl;

　　

The following explains how to pass, if the two-dimensional array variable is a pointer form, then directly define the following function parameter is good

void Function_name (int** arr,int row,int col);

If the two-dimensional array variable is an array, it can be passed by casting to the int** form, such as the following code in the main function:

　　

int Main (intconstChar * argv[]) {    int a[2] [2 ];    Function_name (int* *) A,2,2);}

This method of coercion can also be used for reference.

Another way to pass is to define the template as follows:

Template<typename t>void test1 (t& b) {    << typeid (b). Name () << Endl;} int Main (intconstChar * argv[]) {    int a[2] [ 2 ];     << typeID (a). Name () <<Endl;    Test1 (a);}

The above program is the same as the printing results, indicating that the template type derivation of B is deduced into a two-dimensional array type.

C + + Two-dimensional array delivery