validating for int ONLY, what is the correct code for this code?

Question

 // if user input is negative
 if (h < 0)
 {
     // assign absolute version of user input
     number = Math.Abs(n);
     pictureBox14.Visible = true;
}
else
{
    // else assign user input
        number = n;
    number = 0; // if user input is not an int then set number to 0  
    pictureBox6.Visible = true;
}

What is the correct code for validating to int ONLY? That integer is the only one I want to input in the textbox then the picturebox will appear.

What are `h` and `n`? And I guess your looking for [`int.TryParse()`](https://msdn.microsoft.com/en-us/library/f02979c7(v=vs.110).aspx) — René Vogt, Jan 31 '17 at 14:54
I guess this is a duplicate: http://stackoverflow.com/questions/2751593/how-to-determine-if-a-decimal-double-is-an-integer — Tim Schmelter, Jan 31 '17 at 14:58

score 0 · Answer 1 · answered Jan 31 '17 at 14:55

0

Use int.TryParse method

int value= 0;

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

answered Jan 31 '17 at 14:55

Balaji Marimuthu

1,940
13
13

He uses already the numbers `h` and `n`, so i doubt that string conversion helps – Tim Schmelter Jan 31 '17 at 14:57

Ghasan غسان · Answer 2 · 2017-01-31T14:59:49.920

0

There is no need for a complicated if statement. You can do it like this.

int number = 0;
bool isValid = int.TryParse(userInputString, out number);
number = Math.Abs(number);

if (isValid)
{
    pictureBox14.Visible = true;
}

edited Jan 31 '17 at 14:59

answered Jan 31 '17 at 14:55

Ghasan غسان

5,577
4
33
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He uses already the numbers `h` and `n`, so i doubt that string conversion helps – Tim Schmelter Jan 31 '17 at 14:57
@TimSchmelter Yeah, but he still asks how to validate only integers, which makes me think it might also help him. – Ghasan غسان Jan 31 '17 at 15:01

score 0 · Answer 3 · edited Jan 31 '17 at 15:00

0

You first want to parse user Input, then validate the range:

int ExampleFunc( string userInput )
{
    int nVal;
    if( int.TryParse( userInput, out nVal ) )
    {
        return Math.Abs( nVal );
    }
    else return 0;
}

edited Jan 31 '17 at 15:00

MakePeaceGreatAgain

35,491
6
60
111

answered Jan 31 '17 at 14:57

Fildor

14,510
4
35
67

He uses already the numbers `h` and `n`, so i doubt that string conversion helps – Tim Schmelter Jan 31 '17 at 14:58
@TimSchmelter He talks about getting a value from a TextBox, though. – Fildor Jan 31 '17 at 14:59
@TimSchmelter See "number = 0; // if user input is not an int then set number to 0" how else would you deal with that comment? A variable that already is int cannot be "not int" ... right? – Fildor Jan 31 '17 at 15:02

score 0 · Answer 4 · answered Jan 31 '17 at 15:02

There's no reason to check if the number is negative, just always use the absolute value. Convert will return a 0 value if the string passed to it from the text input cannot be converted properly, so this code handles your question in just one line. If you want the picture box to show based on the int value, test that after the conversion.

int number = Math.Abs(Convert.ToInt32(textInput));

validating for int ONLY, what is the correct code for this code?

4 Answers4