cin.get() vs cin.getline()

Question

why SL compiler doesn't recognizes cin.get() whereas cin.getline() works well?
while using cin.get() it doesn't even show me any errors and neither it works
on other compilers it works fine.
I am attaching two codes for this problem

https://code.sololearn.com/c5ixK3hD5LMj/?ref=app
https://code.sololearn.com/cl61LJNclmMp/?ref=app

Answer 1

Code Playground doesn't recognize that std::cin.get() should prompt for user input when the input stream is empty. However, this doesn't necessarily mean that the function does not work on SL. This is the interesting part. As a workaround, it is possible to write to the input stream, and then extract from the input stream using std::cin.get().

Try doing:

std::cin >> std::ws;
std::cin.get(arr, 10);

This will get user input, store it into the input stream, remove leading whitespaces, and then get() will extract 10 characters from the input stream, store it into arr.

To modify your code:

#include <iostream>
using namespace std;

int main()
{
char str1[40];
cin>>ws;
cin.get(str1,40);
cout << string(str1);
return 0;
}

Answer 2

@Saurabh It is just one of the ways to write to the input stream, which can then be extracted later.

Answer 3

@Saurabh Yes, but there are times when you will want to use it, e.g. input validation before extracting from the input stream and placing it into a variable. It is not a requirement, it is knowing what you can do with it.

Answer 4

It seems that code playground has not included cin.get() in the list of functions to get input.

But if you place a dummy cin>> in the code, the buffer can read input and then cin.get() can use the same input for the array.

So add this line in your code:

#define _ cin>>

Answer 5

I had some spaces in between the command. You cannot ignore those.

Answer 6

thnx for ur help @hatsy!!!!

Answer 7

@kinshuk yep I got it!! thnx again!
@hatsy most of the compilers doesn't require that thing

Answer 8

thnx both of us @hatsy and @kinshuk
kinshuk I tried #define_cin>> but it shows an error
and @hatsy can u explain me why cin>>ws is required while using cin.get()