HTML JavaScript Code

<button onclick="draw()">Draw Square</button>
<canvas height="400" id="canvas" width="500">
</canvas>
<script>
function draw() {
const canvas = document.querySelector('#canvas');
if (!canvas.getContext) {
return;
}
const ctx = canvas.getContext('2d');
// set line stroke and line width
ctx.strokeStyle = 'red';
ctx.lineWidth = 5;
// draw a red line
ctx.beginPath();
ctx.moveTo(100, 100);
ctx.lineTo(300, 100);
ctx.lineTo(300, 300);
ctx.lineTo(100, 300);
ctx.lineTo(100, 100);
ctx.stroke();
}
</script>