Two-dimensional arrays are available as: ① on the stack: int a[4][4] = {...}; ② on heap: int * * = new int *[4]; for (int i = 0; i < 4; i++) A[i] = new INT[4]; In both cases, the two-dimensional array does not have the same parameters for the formal parameter. ① on the stackvoid Fun (int * A, int rownum, int colmunnum)
//Parameter pass by one-dimensional pointer { ...A[r * colmunnum + c] = ...;
//Find the corresponding location according to the column calculation
}void Main (){int A[4][4] = {...};Fun (int *) A, 4, 4);
//cast to one-dimensional pointer upon invocation
} when the ② on the heapvoid Fun (int * * A, int rownum, int colmunnum)
//Parameter pass by two-dimensional pointer { ...A[r][c] = ...;
//directly read the corresponding position
}void Main (){ int * * a = new int *[4];for (int i = 0; i < 4; i++)A[i] = new Int[4]; Fun (A, 4, 4);
//Direct call
} These two ways can not be used together, can be wrong. The specific reason is because:The two-dimensional array allocated on the ① stack is actually similar to a one-dimensional array, and all values are stored continuously. Even if int a[4][4] writes like this, A is also a pointer to an int (*) [4] type, not an int * *, that is, the content is continuously stored for every 4 line breaks;② the Allocated int * * a = new int *[4], its four pointers are assigned separately and the contents are discontinuous. Therefore, it is not possible to locate by R*colnum +c. If the two-dimensional array on the heap is passed in the first way, the output is garbled because the wrong address was read. And the two-dimensional array on the stack in the second way to transmit the error, read the unallocated memory space. Self-summed: http://www.cnblogs.com/dplearning/p/4631541.html
"C language" two-dimensional array to do formal parameters
