What does the code mean?

Question

JavaScript

Hello, tell me please.
I found the code in which the author builds a field for the game.

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

for (var i in context)
{
    context[i[0] + (i[4] || '')] = context[i];
    console.log(context[i]);
}

At the same time, it refers to this site.
// make shortcuts for canvas ops // http://marijnhaverbeke.nl/js1k/
Please tell me what this code means, the properties and methods of the canvas are displayed in the console, but I don’t understand why this is needed and why it takes step 0 and 4 ?!
Thank you!

Answer 1

It's just a reference to another method. Thus, the author will be able to access the method not context.longLongMethod, but context.lL (or not context.meth, but context.m)

Answer 2

strange decision, but interesting.

Answer 3

Pay attention to the URL:
http://marijnhaverbeke.nl/ js1k
This feature is needed for very small code competitions. In real applications, of course, such crap should not be used.