Error when using data tables

[andrew.c.wilson]

Hi,

When I run the code in this project:

https://studio.code.org/projects/applab/lZsPY-1MCD880SVgoe0lxP1WS1bBIn4NWJRQ_vxduPg

I keep getting this error message when I try to set the image and the picture does not appear.

WARNING: Line: 11: setImageURL() url parameter value (undefined) is not a string.

When I copy and paste the image address from the data table it works. I have copied the code from the examples so I am not sure what I am getting wrong. Thanks for your help. Andrew

[mkmietowicz]

Hi @andrew.c.wilson,

I spent a long time trying to fix this code. I set up console.log statements to find out what things were, and they kept coming up undefined. Weird.

Then I looked at Line 1 again:

What were those brackets around getColumn() intended to do? I took them out & the code worked great (link to my remix)! I’d encourage your student to look for simple typographical errors that break the project.

PS: Look at lines 6 & 9 again, and consider what happens to the dog whose pic is at index 0. Think about how to account for that, and then look at how I modified my code.

Hope that helps!
–Michael K.

[jdonwells]

getColumn: one common error and one subtle error explained

The most common error with getColumn by far seems to be wrapping it in [ ]s. You end up with an array (returned by getColumn) inside an array (created by [ ]) and that doesn’t do what you want at all. So just write var cats = getColumn("Cats","Name");. No ( )s and no [ ]s. I wrote a more complete explanation here Everything You Wanted to Know About App Lab Arrays, But Were Afraid to Ask. The subtle error that can result is a race condition. A race condition happens when you have two or more s…

Everything You Wanted to Know About App Lab Arrays, But Were Afraid to Ask

Everything You Wanted to Know About Arrays, But Were Afraid to Ask. [ ] have two uses. One is to create an array and potentially initialize it. So for example: var a = [1,2,3]; That creates an array and assigns it to a variable. Is that variable an array now? No, it is not. Trick question. Variables don’t have types in Javascript. a is a variable that has an array value. It could just as easily hold a number or a string. Variables don’t care. I see a lot of var cats = [getColumn("Cats","Nam…

[andrew.c.wilson]

Hi,

Thanks so much. Code is working perfectly! This is the first time I posted and I am really impressed with the support. I truly appreciate the time you both put into your replies. Thanks again. Andrew

[kiernann]

All of my AP CSP students are receiving the same error about the data tables

[amannerberg1]

Code.org must not be working because we are currently having the same issues.

[rlongoria2]

Yeah, I’m getting the same issue. Must be an issue on their end.

[joseph.clark]

I’m getting the same issue.

[mkmietowicz]

The issue has been fixed! See the post here.

Thank you!

–Michael K.