JS根據文本內容計算占用寬度

/**
 * 使用canvas
 * @param {String} text 文本
 * @param {String} font 字體 如 'normal 12px Arial'
 */
function getTextWidth(text, font) {
  const canvas = getTextWidth.canvas || (getTextWidth.canvas = document.createElement("canvas"))
  const context = canvas.getContext("2d")
  context.font = font
  const metrics = context.measureText(text)
  return metrics.width
}
 
console.log(getTextWidth('IT sol-implementation M', 'normal 12px Arial'));  // 118.4521484375