You are overwriting your only buffer everytime in inFile >> ab;
You read a line in buffer and save the address of buffer somewhere. Next time you read next line in the same buffer and save the exact same address as second line. If you read back your first line you will end up reading updated buffer i.e. last line.
You can change your code to
#include <vector>
#include <string>
#include <fstream>
using namespace std;
int main() {
ifstream inFile;
inFile.open("index.in.txt"); //index.in has in each line a name and at the end there is a "."
string ab; //char ab[11];
int q=0;
vector< string > a(111); //char *a[111];
if (inFile.is_open()) {
while (!inFile.eof()) {
inFile >> ab;
a[q]=ab;
cout<<a[q]<<endl;
q++;
}
}
else cout<<"couldnt read file";
inFile.close();
cout<<"\n"<<ab<<endl; //it shoud be "." and it is
cout<<"\n"<<a[0]<<endl; //it should be "ion" but it gives me "."
return 0;
}
Better use std::string and std::vector instead of arrays.