javascript - 替换选择字段中的选项(不添加)

Question

我有一个选择字段，如下所示:

<select id="field">

我根据页面上另一个 div (OtherDiv) 中找到的值添加选项，如下所示:

window.onload = function onload()
    {
        var OtherDiv = document.getElementById('OtherDiv').innerHTML;
        var result = OtherDiv.match(/SomeRegex/gi);
        var select = document.getElementById("field");
        for(var i = 0; i < result.length; i++)
            {
                var option = document.createElement("option");
                option.value = i+1;
                option.innerHTML = result[i];
                select.add(option);
            }
    }

但是，如果正则表达式没有匹配项，我想为要显示的字段设置一些替代值。我怎样才能最好地实现这一目标？

Answer 1

使用if条件

window.onload = function onload()
{
    var OtherDiv = document.getElementById('OtherDiv').innerHTML;
    var result = OtherDiv.match(/SomeRegex/gi);
    var select = document.getElementById("field");
    if(result.length){
        for(var i = 0; i < result.length; i++)
            {
                var option = document.createElement("option");
                option.value = i+1;
                option.innerHTML = result[i];
               select.add(option);
            }
      }else{
           //add alternative options here
           var option = document.createElement("option");
                option.innerHTML = "No records found"; //whatever text you want to show 
               select.add(option);
      }
}