Pointers

[liengen]

Hi
I have this code in main:

string input[5];
string* ptr[5];

for(int i = 0; i != 5; ++i)
ptr[i] = &input[i];

readLines(ptr, 5);

The function readLines(string *t[], int nmb) shall read some lines (nmb) too the input table via the pointer table. How is this possible?

[Faldrax]

A pointer is just an address in memory.

string* ptr[5] declares an array of 5 pointers, and instructs the compiler that they are pointer to strings.

&input[x] is the address of input[x]

So

for(int x = 0; x != 5; ++x)
   ptr[x] = &input[x];

sets ptr[0] to the address of input[0], etc.

Thus when you call readLines(ptr,5) the function reads the lines to the memory pointed at by ptr, which is the same memory addresses as read using input.