How do i use the built in line function

Question

I know that the beginning of drawing the line after the canvas is set up should look like this
ctx is my canvas context

ctx.moveTo(0,0);
ctx.lineTo(20,20);

I know this should draw a line from point 0,0 to 20,20 but it didnt work for me i think it just sets up the line but doesnt draw it. Please tell me if im missing something.

Answer 1

Is this all your code? Try to make a diagonal line like:

var c = document.getElementById("canvasLine");
var ctx = c.getContext("2d");
ctx.moveTo(0,0);
ctx.lineTo(20,10);
ctx.stroke();