Cannot implicitly convert type string to int

Question

    Console.WriteLine (\"Please enter some numbers\");
        int sum = 0;
        for(;;)
        {
            string input = Console.ReadLine ();
            if          


        

Answer 1

I would rewrite this entirely (Your original error was because you were trying to add a string to an int, and not the parsed input as an int)

Console.WriteLine ("Please enter some numbers");
int sum = 0;

while (true)
{
    int parsedInput = 0;
    string input = Console.ReadLine();
    if (!string.IsNullOrEmpty(input) && int.TryParse(input, out parsedInput))
    {
        sum += parsedInput;
        Console.WriteLine (sum);
    }
    else
    break;
}

Answer 2

to check if the input of the user is right i would prefer

int userInput = 0;
if( int.TryParse( input, out userInput ) == false )
{
     break;
}

This is just an advise and not directly a solution to your problem. There are enough answers =)

Answer 3

int inputParsed = int.Parse (input.ToString ());
            //int sumParsed = int.Parse (sum.ToString ());//no need
            sum = sum + inputParsed ; 

Answer 4

sum = sum + input; //throws an error here

should be:

sum = sum + inputParsed ;

You are using the original input instead of the parsed value. And you don't need sumParsed because you just keep the total sum in sum and you do no need to cast the int to a string and then parse it back to an integer.