Examples look at two-dimensional arrays, pointers, two-dimensional array pointers

Routines:

/******************************************************** file Name: Routine * * File Description: Example of two-dimensional array, pointer, two-dimensional array pointer * * Creator: jesse** version number: * * Modify Record: /#include <stdio.h> #define ROW  3#define Line 3void Main (void) {const int Array[row][line] = {//array is a pointer to int [line] {11,12,13},{21,22,23},{31,32,33}};unsigned  Char row, line;const int *pr = Null;//int *PR is a pointer to int *, const int (*ARRPR) [Line] = Null;//int (*ARRPR) [row] is a pointer to int A pointer to [line], with an array of the same type const int **DPR = Null;//int **DPR is a pointer to the int*, same as &PR. Two-dimensional array value printf ("///              two-dimensional array value: Array[row][line]              //\n"); for (row=0; row<row; row++) {for (line=0; line<line; line++) printf ("row:%d,line:%d,value:%d    ", row, line, Array[row][line]);p utchar (' \ n ');}}

The results are printed as follows:

Here we use a single-layer pointer to output the values of the two-dimensional array:

The pointer and the two-dimensional array value PR = array;//force the type of array (int [line]) to be converted to the type (int *). PS: When you add 1, you add sizeof (int) instead of 3*sizeof (int). for (row=0; row<row; row++) {for (line=0; line<line; line++) printf ("row:%d,line:%d,value:%d    ", row, line, * (pr +row*3+line));p Utchar (' \ n ');}

PR = array; The double-decker pointer is cast to a single-level pointer, which is the PR-plus 1 plus the sizeof (int), and because the array is stored in a contiguous stack, the value of the array can be output with * (Pr+row*3+line).

Here we use a two-dimensional array pointer to output the values of a two-dimensional array:

Two-dimensional array pointers and two-dimensional array values ARRPR = ARRAY;//ARRPR with an array of the same type of pointer printf ("//              two-dimensional array pointer and two-dimensional array: arrpr[row][line]              //\n"); for (row = 0; row<row; row++) {for (line=0; line<line; line++) printf ("row:%d,line:%d,value:%d    ", row, line, Arrpr[row][line]);p Utchar (' \ n ');}

ARRPR = array; Equivalent to assigning a two-dimensional array pointer to another two-dimensional array pointer. So ARRPR can be used like an array: Arrpr[row][line]

Here we use a two-level pointer to output the values of the two-dimensional array:

Two-level pointers and two-dimensional array values//method One: printf ("//              two-layer pointer and two-dimensional array: * (*dpr+line)              //\n"); for (row=0; row<row; row++) {PR = Array[row]; DPR = &pr;for (line=0; line<line; line++) printf ("row:%d,line:%d,value:%d    ", row, line, * (*dpr+line)); Putchar (' \ n ');} Method Two: printf ("//              two-layer pointer and two-dimensional array: **DPR              //\n"); for (row=0; row<row; row++) {for (Pr=array[row]; Pr-array[row] <LINE; pr++) printf ("row:%d,line:%d,value:%d    ", row, line, **DPR);p Utchar (' \ n ');}

I tried it before.

DPR = array;    Force the type of array (int [line]) to be converted to (int *)

Whether using the PR output method output, or using the output method of ARRPR output, the results obtained are wrong.

A variable of type int **DPR cannot directly accept the address of a two-dimensional array, and for a two-dimensional array, DPR is equivalent to a pointer of type int (*ARRPR) [] and does not indicate how many int types are included, which is an error.

So the first level of the pointer must indicate the width:

PR = Array[row];

The second-level pointer then points to the first-level pointer:

DPR = ≺

And then in use:

* (*dpr+line)

The output array.

Examples look at two-dimensional arrays, pointers, two-dimensional array pointers