为什么所有画布示例都使用ctx？

Question

Is this a requirement or a convention? If it's a convention what's the reason? Ctx doesn't seem especially memorable or intuitive.

eg

var ctx = document.getElementById('canvas').getContext('2d');

Answer 1

It is a shorthand for the word "context". That's it.

Of course you can use whatever name you like - there is no real naming convention in this instance.

Answer 2

It is just name for variable. It could be anything. Ctx is just short word for ConTeXt .

Answer 3

这是一个惯例，因为大多数开源浏览器中的画布使用Cairo，而在开罗，它们被称为“上下文”。

Answer 4

it's exactly the same if you do

var context = document.getElementById('canvas').getContext('2d');

or

var whatever = document.getElementById('canvas').getContext('2d');

I think "ctx" is really explanatory and short enough :)

Answer 5

可能是因为这些例子正在教授一些东西，并且写的人想要确保读者知道ctx是画布上下文，因为ctx是上下文的缩写，但是当你可以写“ctx”时写“上下文”太无聊了。