+ 2

Could you please explain more about accessing arrays by pointers?

the array is a pointer to the first element what if I want to access the second element using pointer

1st Nov 2017, 5:05 AM
aly gaber
aly gaber - avatar
1 Antwort
+ 5
#include <iostream> using namespace std; int main() { int arr[] = {1, 2, 3, 4, 5, 6, 7, 8, 9}; int *p = arr; cout << arr << endl; // address of arr (first element) cout << *arr << endl; // value of first element in the arr cout << p << endl; // address of arr (first element) cout << *p << endl; // value of first element in the arr p++; // increment the pointer to the next memory address cout << p << endl; // address of arr (second element) cout << *p << endl << endl; // value of second element in the arr p = arr; // reset the address held by the pointer p to the begining of the array // loop over the array using a pointer // 9 is one memory address past the end of the array // this is used when using < less than operator // as using the last elements address would only // get up to the element before it for(int *i = arr; i < &arr[9]; i++) { cout << *i << " "; } cout << endl; // alternate way of gettting the length/size of an array for(int *i = arr; i < &arr[sizeof(arr)/sizeof(arr[0])]; i++) { cout << *i << " "; } return 0; } You can use pre and post fix operators to move the pointer forward and backward over the array. You can also just use basic math to add/subtract to the pointer. (be careful) Hope this helps.
1st Nov 2017, 6:44 AM
ChaoticDawg
ChaoticDawg - avatar