CODEWITHSUNDEEP
c#asp.net
challengeAccepted
challengeAccepted

Reputation: 7590

Adding textbox values

In Asp.net using c# ,I am having

int sum = Convert.ToInt32(txtbox1.Text) + Convert.ToInt32(txtbox2.Text);

When i have an empty textbox, i get the error "Input string is not in a correct format".

So, I am wondering if there is a simple way to add textbox values only they are integers, if not take the textbox value as 0.

Thanks in advance!

Upvotes: 0

Views: 3951

Answers (6)

D Stanley
D Stanley

Reputation: 152521

You can either set the default value of the TextBox to 0, or use TryParse:

int val1, val2;
Int.TryParse(txtbox1.Text,out val1));
Int.TryParse(txtbox2.Text,out val2));
int sum =  val1 + val2;

Note that you do not need to set the values to 0 if the parse fails since they will be 0 anyways. If you want to be explicit, however:

int val1, val2;
if(!Int.TryParse(txtbox1.Text,out val1))) val1 = 0;
if(!Int.TryParse(txtbox2.Text,out val2))) val2 = 0;
int sum =  val1 + val2;

Upvotes: 1

evanmcdonnal
evanmcdonnal

Reputation: 48076

Use try parse to ensure that the textbox's contain valid input (that or limit the input to only numbers).

 int x, y, result;
 if (int.TryParse(txtbox1.Text, x)
 {
     if (int.TryParse(txtbox2.Text, y)
     {
          result = x + y;
     }
     else
         //error message
 }
 else
     // error message

Upvotes: 1

Muhammad Hani
Muhammad Hani

Reputation: 8664

use TryParse ..

int iFirstVal= 0;
int iSecondVal= 0;

int.TryParse(txtbox1.Text, out iFirstVal))
int.TryParse(txtbox2.Text, out iSecondVal))

int sum = iFirstVal + iSecondVal

Upvotes: 0

Icarus
Icarus

Reputation: 63956

Write an Extension method for this

public static int NullOrEmptyToZero(this string s)
{
    return string.IsNullOrEmpty(s)? 0: ConvertToInt32(s);
}

And use it like so:

int sum = txtbox1.Text.NullOrEmptyToZero() + txtbox2.Text.NullOrEmptyToZero();

Upvotes: 1

tam tam
tam tam

Reputation: 1900

int integer;
 Int32.TryParse(Textbox1.Text, out integer)

int integerSecond
 Int32.TryParse(Textbox2.Text, out integerSecond)

It will return a bool so you can see if they entered a valid integer

Alternatively you could also use some validators:

<asp:CompareValidator runat="server" Operator="DataTypeCheck" Type="Integer" 
 ControlToValidate="ValueTextBox" ErrorMessage="Value must be a whole number" />

If there is a specific range of values that are valid (there probably are), then you can use a RangeValidator, like so:

<asp:RangeValidator runat="server" Type="Integer" 
MinimumValue="0" MaximumValue="400" ControlToValidate="ValueTextBox" 
ErrorMessage="Value must be a whole number between 0 and 400" />

Upvotes: 1

Berni
Berni

Reputation: 510

You can use Int32.TryParse method

Documentation MSDN

Upvotes: 3

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