javascript - 如何将 cm 值转换为英寸并将文本 "cm"替换为 "in"？ Javascript

Question

我正在尝试重新创建我见过的服装测量图表，但使用纯 Javascript。我无法弄清楚如何获取 innerhtml 中的数值并将其乘以/除以 * 2.54。另外，我想在数字末尾添加“cm”或“in”来表示测量系统。
https://jsfiddle.net/kud8sj7w/5/

<div id="xs-sizes">
        <li class="measurement" style="left: 15%; top: 33%;">
            63.5
        </li><li class="measurement" style="left: 48%; top: 16%;">
            43.5
        </li><li class="measurement" style="left: 48%; top: 79%;">
            50.5
        </li><li class="measurement" style="left: 48%; top: 50%;">
            43
        </li><li class="measurement" style="left: 83%; top: 62%;">
            64.5
        </li>
        

 function convert() {
      var measurements = document.getElementsByClassName("measurement");
      
       for(var i = 0; i < measurements.length; i++){
       
          measurements[i].innerHTML = valNum * 2.54;
       }
  }

Answer 1

您需要存储当前状态以了解是否需要转换。在您的情况下，最初是“CM”

 let cur_measurement = 'CM';

 function convert() {
   let measurements = document.getElementsByClassName("measurement");
   let CM = document.querySelector('input[value="CM"]');
   let IN = document.querySelector('input[value="IN"]');
   
   let ratio = 0;
   if(CM.checked && cur_measurement != 'CM'){
        ratio = 2.54;
      cur_measurement = 'CM';
   } else if (IN.checked && cur_measurement != 'IN' ){
        ratio = 1/2.54;
      cur_measurement = 'IN';
   }

   for (var i = 0; i < measurements.length; i++) {
        let cur_val = parseFloat(measurements[i].innerText);
        measurements[i].innerText = Math.round(cur_val * ratio * 10) / 10;
   }
 }