如何获取段落中字符串的宽度？

<span id="text">Hello, World!</span>

#text {
  font-family: Arial, sans-serif;
  font-size: 16px;
}

var textElement = document.getElementById("text");
var textWidth = textElement.offsetWidth;
console.log("Text width: " + textWidth + "px");

<canvas id="canvas"></canvas>

var canvas = document.getElementById("canvas");
var context = canvas.getContext("2d");
var text = "Hello, World!";
context.font = "16px Arial, sans-serif";
var textWidth = context.measureText(text).width;
console.log("Text width: " + textWidth + "px");