Why does it not work?

Question

#include <iostream>
#include <string>
using namespace std;

int main(){
string a;
cin >> a;
size_t pos = a.find("3");
a.replace(pos, 1, "three");
cout << a;
return 0;
}

Answer 1

Because SoloLearn separates inputs by (any amount of) spaces and/or newlines for C and C++ (maybe, some more?).

[edit]
I just discovered that all (at least major) C++ compilers read upto space or newline when it is used thus.
Try to use this line instead of "cin >> a;":
cin.getline(a, 101);
(you can replace 101 with any value, but 101 is the best for SoloLearn Playground)
[Source and more information: https://stackoverflow.com/questions/5838711/stdcin-input-with-spaces]

Answer 2

get Found a fix apparently getline(cin,a) works for strings cin.getline mostly works for arrays sorry for taking your time and thank you for your help.

Answer 3

Sorry. I asked the question incorrectly it works if I do it normally but does not work with cin.Ex.
If I say string a = "hello 3" it works but when I do it as input it does not.

Answer 4

Labib Wadi, this is exactly what I said. SoloLearn and most of major C++ compilers read <string> or <char []> input until reaches newline *or space*.
Use "cin.getline(string_to_store, max_length);" instead of "cin >> string_to_store;" for your program to accept input with spaces. It finishes reading until newline or when input exceeds (max_length - 1) characters.

To be honest, I stuck with this problem, too. This was not small project where I was constantly adding new features, and thus I was adding some features without ability to test them until I got it by myself (now I plan to return to it).
Hope it helped and you understood.

Answer 5

get Still doesn't work. Returns an error,sorry.