c＃声明变量的方法

Question

i am making a class in which i have used method .they variables are declared directly in method paramter.why i cant declare int below like string.

class studentinfoget
{
    static void Getstudnetinformation(string firstname, string lastname, string birthday, string address, int cellnumber, int homenumber)

    {
        Console.WriteLine("enter your first name");
        firstname = Console.ReadLine();
        Console.WriteLine("enter your LAST NAME");
        lastname = Console.ReadLine();
        Console.WriteLine("enter your brithday ");
        birthday = Console.ReadLine();
        Console.WriteLine("enter birthday");
        address = Console.ReadLine();
        Console.WriteLine("enter address");
        cellnumber = Console.ReadLine();
        Console.WriteLine("enter adress");


    }

Error for this code is

CS0029 C# Cannot implicitly convert type 'string' to 'int'

Answer 1

You can use int.TryParse() to convert the input into an integer.

int.TryParse(Console.ReadLine(), out cellnumber);

However, if the test fails, cellnumber will be 0.

A cell number may not necessarily be an integer though - you could have somebody entering the cell number as "XXX-XXX XXXX" , or it may have more than 10 digits, in which case you may exceed the int.MaxValue of 2,147,483,647. Also, the starting digit might be a 0, which would then be stripped out when stored and render the phone number invalid.

In this case I would recommend storing the value as a string as at least then the user-entered format will be preserved.

Answer 2

cellnumber is declared as an int but Console.ReadLine returns a string . You need to convert the entered text to a number:

int.TryParse(Console.ReadLine(), out cellnumber);

TryParse is used to handle invalid input - if the user enters Phone or something that isn't a number TryParse won't throw an exception, it will return false but execution will continue.

Answer 3

you may use cellnumber = Int32.Parse(Console.ReadLine());

but you should change cellnumber and homenumber to string variable.