//二维指针的开辟与释放 int **b = NULL; b = new int*[10]; for(int i = 0; i != 10; ++i) {      b[i] = new int[50];      memset(b[i], 0, sizeof(int)*50); } //这样就在堆上开辟了int类型的二维指针，大小为10*50，相当于在堆上一个二栈数组int b[10][50]; for(int i = 0; i != 10; ++i) {      delete []b[i];      b[i] = NULL; } delete []b; b = NULL; //三维指针的开辟与释放 int ***a = NULL; a = new int**[10]; for(int i = 0; i != 10; ++i) {     a[i] = new int*[50];     for(int j = 0; j != 50; ++j)     {         a[i][j] = new int[30];         memset(a[i][j], 0, sizeof(int)*30);     } } //这样就在堆上开辟了int类型的三维指针，大小为10*50*30，相当于在栈上一个二维数组int a[10][50][30]; for(int i = 0; i != 10; ++i) {     for(int j = 0; j != 50; ++j)     {        delete []a[i][j];        a[i][j] = NULL;               }     delete []a[i];     a[i] = NULL; } delete []a; a = NULL;