CODEWITHSUNDEEP
c#stringdatatabledouble
user682417
user682417

Reputation: 1518

trying to convert the string to double

I have two values coming from database i need to convert these values into double i have done like this i ahve just mentioned like this just as local variables

            string val;
            string dpayment;

and i am taking the values from database by the following query

  if (dt != null)
  {
    if (dt.Rows.Count > 0)
    {


        dpayment = Convert.ToDouble(dt.Rows[1]["monthlyamount"]).ToString("0.00");

     val= Convert.ToInt32( dt.Rows[3]["value"]).ToString();       
    }
  }

i am using these values and doing the operation like this 

                 double eqvperiod = Convert.ToDouble(val / dpayment).ToString();

but it was giving error

operator '/' cannot be used as a operands of type string and string.

any one can help on this

my final result is i want to convert the values coming from databases to double and i have to do the operations on this values

Upvotes: 0

Views: 1214

Answers (5)

lelewin
lelewin

Reputation: 559

How about this?

double eqvperiod = 0.00;

if (dt != null && dt.Rows.Count > 0)
{
    eqvperiod = Convert.ToDouble(dt.Rows[1]["monthlyamount"]) /
                  Convert.ToInt32(dt.Rows[3]["value"]);
}

Upvotes: 0

Avinash
Avinash

Reputation: 1

Try this:

double eqvperiod = (Convert.ToDouble(val) / Convert.ToDouble(dpayment));

Upvotes: 0

Metal10k
Metal10k

Reputation: 71

You can also do double.Parse("0.010")

this also works for int, short, decimal, and probably any other numeric types

Upvotes: 0

dahlbyk
dahlbyk

Reputation: 77530

Convert to double before dividing:

double eqvperiod = Convert.ToDouble(val) / Convert.ToDouble(dpayment);

And actually, you don't need to Convert() then ToString() then Convert() a second time:

int val = 0;
double dpayment = 0.0;

if (dt != null && dt.Rows.Count > 0)
{
     dpayment = Convert.ToDouble(dt.Rows[1]["monthlyamount"]);

     val= Convert.ToInt32( dt.Rows[3]["value"]);       
}

double eqvperiod = val / dpayment;

Upvotes: 2

DoctorMick
DoctorMick

Reputation: 6793

Why have you declared val and dpayment as strings? If you want them to be numeric types then change the variable declaration and remove the ToString, i.e.

int val;
double dpayment;

dpayment = Convert.ToDouble(dt.Rows[1]["monthlyamount"]);
val= Convert.ToInt32( dt.Rows[3]["value"]);

Upvotes: 2

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