Why can't I explicitly cast an int to a string?

Question

If I try to do this it doesn't work:

static void Main(string[] args)
{
    int a = 5000;
    Console.WriteLine((string)a);
}

But somehow this works fine:

static void Main(string[] args)
{
    int a = 5000;
    Console.WriteLine(a + "");
}

Why is that? Is it because the first is trying to change the base type and the second just appends the value to the string?

Answer 1

int cannot be cast to string (1), but there is an operator + that accepts int as left-hand argument and string as right-hand argument (2). This operator converts the int to string and concatenates the two strings.

A better approach would probably be to just use Console.WriteLine(a); which would call a.ToString() for you.

Answer 2

So you are getting a compile time error right? The problem is is that int does not explicitly cast to string.

So

(string)a

is not valid code but

a + ""

mean that the code will work because it basically get translated to

a.ToString() + ""

So the int gets converted into a string value

Answer 3

You should use:

static void Main(string[] args)
{
    int a = 5000;
    Console.WriteLine(a);
}

that implicitly calls a.ToString()