Here's an example.
I wish it was possible to say:
fillCircle(150, 150, 50);
So I define a function:
function fillCircle (x, y, radius) {
ctx.beginPath();
ctx.arc(x, y, radius, 0, Math.PI * 2);
ctx.fill();
}
We've still got to spell out the three lines of code involved in making a circle, but once you've done so once, you can use "fillCircle" very concisely and conveniently from then on.