How do I compare input text to variable

Hi,

I'm trying to make some elearning math content.

I need to be able to show on screen a question (eg 1 + 2), then have a input text field that the user will enter the answer into.

Once they've entered the answer they need to click a check answer button that then marks the question right or wrong.

Can someone point me in the right direction, I've look through the docs and the forum but can't see anything similar to this.

Thanks

You should use a textbox. You can access the textbox content by using textbox.Text, so, you just compare this to your correct answer, when the button is pressed, and check if they match.

Yes, I already have a textbox, but I don't know how to access/compare when the button is pressed?

Something like this?

On button clicked
System -> Compare two values -> Int(TextBox.Text) equals CorrectAnswer
[/code:30aghlwo]

.Text property of the TextBox stores string data, and I assume that the CorrectAnswer variable stores numbers.
That's why to compare them you need to use Int(), which converts string into number. 

Another way:
[code:30aghlwo]On button clicked
TextBox -> Compare text -> Str(CorrectAnswer)[/code:30aghlwo]

Here is an opposite thing - you need to convert the number CorrectAnswer into string, you can do it with Str() function.

thanks, that worked perfectly

one further question... is there such a thing as null values in Construct?

I have it set that if the Textbox is equal to CorrectAnswer its correct, else its wrong, but I would like it that if nothing has been entered into the Textbox then nothing happens

I've tried

Int(TextBox.Text) equals " "
Int(TextBox.Text) equals Null
Int(TextBox.Text) equals NaN[/code:378j1uy1]

So I'm guessing this isn't the way to do it in Construct

No, there is no Null in C2. Empty string is always "" (quotes without space in between).

sorry it was a typo above I meant ""

currently I have

Button On Clicked
System -> Compare Two Values -> int(TextBox.Text) = ""
Text -> Set text to "empty"[/code:21sy3pkg]

I set the Text field up so I could see if there function was working... which it isn't

That's because you are comparing number with string!

Int() is number and "" is string.

You should compare either TextBox.Text="" or Int(TextBox.Text)=0

ah yes, of course

using TextBox.Text="" works fine

thanks