rishiag rishiag - 1 year ago 74
C++ Question

Getline keeps on getting newline character. How can I avoid this?

Basically I first takes an integer as input and then test case follows. My each test case is an string. I am suppose to print the string back if the starting patten of string matches "HI A" and it is case-insensitive. I wrote the code below to accomplish to this. My problem is that when I press enter after each input, getline takes newline character as new input. I have tried to tackle this by using extra getline after each input but the issue is still there. Program gets stuck in the loop even though I have put a break condition. What am I doing wrong?

#include <iostream>
#include <string>
using namespace std;
int main(){
int N;
cin >>N;
string nl;
for (int i=0;i<N;i++){
string s;
//cout <<"string"<<s<<endl;
int flag=0;
if ((s.at(0)=='h'||s.at(0)=='H')&&(s.at(1)=='i'||s.at(1)=='I')&&(s.at(2)==' ')&&(s.at(3)=='a'||s.at(3)=='A')) flag=1;

if (flag==1) cout << s;
//cout << "not " <<s;
string ne;
cout << "i="<< i<<endl;
if (i==N-1) {break;}


Here is sample input:

Hi Alex how are you doing
hI dave how are you doing
Good by Alex
hidden agenda
Alex greeted Martha by saying Hi Martha

Output should be:

Hi Alex how are you doing

Answer Source

Your cin >>N stops at the first non-numeric character, which is the newline. This you have a getline to read past it, that's good.

Each additional getline after that reads the entire line, including the newline at the end. By putting in a second getline you're skipping half your input.