Canvas javascript error

Question

Ok guys Hey, i don't undestand what is wrong here they say it's an error at line 2 In javascript canvas.getContext
https://code.sololearn.com/WZ89E8a70Q87/?ref=app

Answer 1

Add all JS into onload callback function.
https://code.sololearn.com/W1JT9X3yNqox/?ref=app

Answer 2

onload = function () {
// add your javascript codes here

}

Answer 3

ctx=canvas.getContext("2d")

Answer 4

Ok thanks u a lot !

Answer 5

When I wrote this in my computer that's work well but here no.. :(

Answer 6

Can you show me an example please ?

Answer 7

Nan bro :/