CODEWITHSUNDEEP
c#mathoperator-keyword
Blaze M
Blaze M

Reputation: 150

+ Operator c# with string

I have got this code down below which should multiply two variables and add to it amount from textbox kpriplac. but when the multiplied value is 10 and kpriplac value is for example also 10 the output is 1010. But I need that output to be 20. I have also checked this

Where do I make a mistake? Thanks for your time reading this.

if (double.TryParse(comboBoxText, out comboxValue) && int.TryParse(textBox16.Text.Trim(), out textboxValue))
{
    textBox19.Text = ((comboxValue * textboxValue) + (kpriplac.Text)).ToString();
}

Upvotes: 1

Views: 1489

Answers (5)

Zaheer Ahmed
Zaheer Ahmed

Reputation: 28588

+ operator with strings operate as concatenate operator. You need to parse string to int or float.

for example:

textBox19.Text = ((comboxValue * textboxValue) + Convert.ToInt32(kpriplac.Text)).ToString();

Edit

Pleas make sure kpriplac.Text is:

  • Is not empty
  • Not contains only spaces
  • Not contains the character or non convertible string.

If it then handle accordingly.

Convert Class Msdn

Upvotes: 2

Ehsan
Ehsan

Reputation: 32729

You face this because

 (comboxValue * textboxValue)

is an integer,whereas 

 kpriplac.Text

is a string

In C# string + int = string. So lets say multiplication returns you 10. And you have got 10 in your text box as well

so what will happen is

        10 + "10"  = 1010

Change your code to

 if (double.TryParse(comboBoxText, out comboxValue) && int.TryParse(textBox16.Text.Trim(), out textboxValue))
 {
    int tempValue = 0;
    if(int.TryParse(kpriplac.Text,out tempValue))
         textBox19.Text = ((comboxValue * textboxValue) + tempValue).ToString();
 }

Upvotes: 1

KappaG3
KappaG3

Reputation: 671

You need to call int.Parse on every string, and then multiply or add the parsed values together, finally converting them back to string.

Use int.Parse only if you're sure that the given string is indeed an integer. If it isn't, exceptions are thrown. If you're unsure and want to handle them manually, use int.TryParse instead.

Upvotes: 1

lc.
lc.

Reputation: 116538

As it stands, your code is adding a number to a string which is implicitly calling ToString() on the (comboxValue * textboxValue) expression and performing string concatenation.

You need to parse the value in kpriplac.Text into a numeric type as well, in much the same manner you are doing for comboBoxText and textBox16.Text.

Upvotes: 2

zxc
zxc

Reputation: 1526

Try this

Convert.ToInt32(((comboxValue * textboxValue) + (kpriplac.Text))).ToString();

Upvotes: 0

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