问绘制时显示线条的HTML5画布

EN

let canvas = document.querySelector('canvas');
let ctx = canvas.getContext("2d");

let width = canvas.width / 10;
let height = canvas.height / 10;
console.log(width, height);

ctx.fillStyle = '#000';
ctx.fillRect(0, 0, canvas.width, canvas.height);

for (let x = 0; x < 10; x++)
  for (let y = 0; y < 10; y++) {
    ctx.fillStyle = (x + y) % 2 ? '#ffe' : '#eef';
    ctx.fillRect(x * width, y * height, width, height);
  }

canvas {
  outline: 1px solid;
}

<canvas width=500 height=503></canvas>