String problems

1 
type or paste code here
```bool isPalindrome(int N)
	{
		string str = "" + N;
     
		int len = str.length();
		for (int i = 0; i < len / 2; i++) {
			if (str[i] != str[len - 1 - i])
				return false;
		}
		return true;
	}
why its  working properly?
But When
bool isPalindrome(int N)
	{
		string str = "" + N;
                  cout<<str; // this line displaying error
		
		}
		return true;
	}
why cout<<str displaing error?
2

You cannot assign int directly to string .

Instead of this 
string str = "" + N;

use this

string str = to_string(N);
// here to_string STL converts int to string .You can read about to_string STL from google.