Canvas question?

Question

When you play around with the examples in a lesson, it works fine. But if try your own it doesn't work.
for eg.
var c = document.getElementById("canvas");
var ctx=c.getContext("2d");
always results in: cannot read property 'getContext' of null line blahblah
Why does this happen?

Answer 1

If you wrote the code in the JS tab, you need to wrap it inside window.onload so that the document is loaded first before the script.
window.onload = function(){
var c=document.getElementById("canvas1");
var ctx=c.getContext("2d");
}

Answer 2

should really make a post explaining this issue and how to handle it (with pics)
just too lazy ._.

Answer 3

just added a (long long long) post regarding this issue
https://www.sololearn.com/post/7444/?ref=app
can also refer to it any other users who encounter this

Answer 4

Smithy , it's actually a common problem for beginners here on Sololearn.
I also struggled about that issue before.😅

Answer 5

Good luck👍

Answer 6

Thank you Jonathan Pizarra I will try that

Answer 7

Jonathan Pizarra glad I'm not the only one. Your solution works fine, now to try some of the other ones they mentioned. I still trying to get a circle to work, but not giving up on it yet😊

Answer 8

Jonathan Pizarra Thanks mate

Answer 9

Burey Thank you

Answer 10

Burey it could be handy, or maybe I'm the only one having trouble with it 😂😂😂