console 命令行工具 X clear

console

function draw(){
    const ctx = document.getElementById('canvas').getContext('2d')
    ctx.shadowOffsetX = 2;
    ctx.shadowOffsetY = 2;
    ctx.shadowBlur = 5;
    ctx.shadowColor = "rgba(0, 0, 0, 0.5)";
    ctx.fillRect(100,100,100,100)
}

draw()

<canvas id="canvas" width="1000" height="1000"></canvas>