How to validate user input for whether it's an

Question

It tells me that it can't convert int to bool. Tried TryParse but for some reason the argument list is invalid.

Code:

private void SetNumber(string n)
{
    // if user input is a number then
    if (int.Parse(n)) 
    {
        // if user input is negative
        if (h < 0)
        {
            // assign absolute version of user input
            number = Math.Abs(n); 
        }
        else 
        {
            // else assign user input
            number = n;
        }
    }
    else
    {
        number = 0; // if user input is not an int then set number to 0  
    }
}

Answer 1

    private void SetNumber(string n)
    {
        int nVal = 0;

        if (int.TryParse(n, out nVal))
        {
            if (nVal < 0)
                number = Math.Abs(nVal);
            else
                number = nVal;
        }
        else
            number = 0;
    }

Answer 2

//[e-mail]
//In my knowledge i did this in simple way thanks for watch my code 
 static void Main(string[] args)
    {
        string a, b;
        int f1, f2, x, y;
        Console.WriteLine("Enter two inputs");
        a = Convert.ToString(Console.ReadLine());
        b = Console.ReadLine();
        f1 = find(a);   
        f2 = find(b);   

        if (f1 == 0 && f2 == 0)
        {
            x = Convert.ToInt32(a);
            y = Convert.ToInt32(b);
            Console.WriteLine("Two inputs r number \n so tha additon of these text box is= " + (x + y).ToString());
        }
        else
            Console.WriteLine("One or tho inputs r string \n so tha concadination of these text box is = " + (a + b));
        Console.ReadKey();

    }
        static int find(string s)
        {
        string s1 = "";
        int f;
         for (int i = 0; i < s.Length; i++)
            for (int j = 0; j <= 9; j++)
            {
                string c = j.ToString();
                if (c[0] == s[i])
                {
                    s1 += c[0];
                }
            }

        if (s==s1)
            f= 0;
        else
            f= 1;

        return f;
    }

Answer 3

You could try something like below using int.TryParse..

        private void SetNumber(string n)
        {
            int parsed = -1;
            if (int.TryParse(n, out parsed)) //if user input is a number then
            ...

The reason there are complaints that it cannot convert an int to a bool is because the return type of int.Parse() is an int and not a bool and in c# conditionals need to evaluate bool values.

Answer 4

Just use this:

int i;
bool success = int.TryParse(n, out i);

if the parse was successful, success is true.

If that case i contain the number.

You probably got the out argument modifier wrong before. It has the out modifier to indicate that it is a value that gets initialized within the method called.

Answer 5

int.Parse will give you back an integer rather than a boolean.

You could use int.TryParse as you suggested.

int parsedValue;
if(int.TryParse(n, out parsedValue))
{
}

Answer 6

int.Parse will convert a string to an integer. Current you have it within an if statement, so its treating the returned value of int.Parse as a bool, which its not.

Something like this will work:

private void SetNumber(string n)
{
    int num = 0;
    try{
        num = int.Parse(n);
        number = Math.Abs(num);
    }catch(Exception e){
        number = 0;
    }   
}