How do I use the J and x variables in Thunkable?

Questions about Thunkable
1

Hi
I am trying to google around and want to learn about the J and X variables in Thunkable. How are they ment to be used?

ex, “For each Item J in list, do”…
I understand it’s a loop but what does the J stands for?

Thanks!

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2

The “j” is just a variable that holds each list item as the loop iterates.

So let’s say you have a list with items {1,22,83}. If you run this code:

For each item j in list do
     set label's text to j
     wait 1 second

Then you will see…
1
22
83

…with a second pause between each number.

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3

Hi.
Thanks for the explanation! So I use this within an existing list if I want to do anything with the items in that list? And the J variable will hold these items until I have told what to do with them?
Is that correct?

Does it stands for anything (the J) or is it just like a x/y in a diagram?

Thanks!

4

Yes, that’s correct.

The “j” does not stand for anything. It’s similar to x or y as a math variable. In fact, you can create your own loop variables and call them whatever you want. But it’s easiest to just use the default “i” or “j” variables.

5

Great, thanks!

I have noticed there is an ”x” in that block as well.
Is that the same thing as the ”j”? Is it to use different loops with the same material/list/items?

6

Hi there,

The j variable is a local variable used in loops, as seen in the Control blocks.

The x variable is a local variable used in functions.

Both of these can be renamed, those are just the default names.

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7

Thanks Jane! Just out of curiosity, are these variabels “hardcoded” to functions/loops? I mean, is it just a matter of order or is it simply not not possible to use j for functions and vice versa in a technical perspective ? Thanks

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8

You can use whatever variable you want in whatever place. Click in the variable, for example, “j” and the popup list has a rename option.

image

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9

Ok so its just a matter of order then? This is how people likes to use it: x for functions and j for loops?

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10

:+1:

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11

These are just conventions! You’ll see similar default naming strategies in guides for other programming languages. Another classic is using i in the ‘count with [i] from [1] to [10] by [1]’ block, also seen in the control blocks.

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