SOURCE

console 命令行工具 X clear

                    
>
console
var canvas=document.getElementById("dcanvas");
	var context=canvas.getContext("2d");
	 var x=150;
	 var y=300;
	 var radius=100;
	 var strart=0;
	 var end=2*Math.PI; 
	 context.arc(x,y,radius,strart,end);
	 context.fillStyle="#A5ADF9";
	context.lineWidth=18;
		context.strokeStyle = '#7787FC';
		context.lineWidth=18;
	 context.fill();
	 context.stroke();


 
<canvas id="dcanvas" width="500" height="500"></canvas>
.cans {
  width:500px;
  height:500px;
  background:yellow;
}