javascript - 2x if 语句 (sel.options[sel.selectedIndex].value)

Question

我似乎无法正常工作，我想检查是否选择了 AM-1 路线，然后是否也选择了值“1vlucht”并相应地更改 innerHTML。这可能吗？我也尝试过 && 但没有运气。

我什至不确定你是否可以为 1 个功能使用 2 个标签。第一次尝试这些功能。

        function priceRoute(sel)
        {
        	// PRIJZEN
        	if ( sel.options[sel.selectedIndex].value == "AM-1" ) 
            {
             
                if ( sel.options[sel.selectedIndex].value == "1vlucht" )
                {
            	    // PRIJS PER VLUCHT
            	    document.getElementById("pricePervlucht").innerHTML = "100,-";
                    document.getElementById("pricePervlucht2").value = "100,-";
                    
                    // TOTAAL PRIJS
                    document.getElementById("priceTotaal").innerHTML = "100,-";
                    document.getElementById("priceTotaal2").value = "100,-";
                    
                    // BESPARING
                    document.getElementById("priceBesparing").innerHTML = "0,-";
                    document.getElementById("priceBesparing2").value = "0,-";
                }
        
            	else if ( sel.options[sel.selectedIndex].value == "2vluchten" )
            	{
            	    // PRIJS PER VLUCHT
            	    document.getElementById("pricePervlucht").innerHTML = "90,-";
                    document.getElementById("pricePervlucht2").value = "90,-";
                    
                    // TOTAAL PRIJS
                    document.getElementById("priceTotaal").innerHTML = "180,-";
                    document.getElementById("priceTotaal2").value = "180,-";
                    
                    // BESPARING
                    document.getElementById("priceBesparing").innerHTML = "20,-";
                    document.getElementById("priceBesparing2").value = "20,-";
            	}
            }
        }

<select name="listingtypeRouteAM" id="listingtypeRouteAM" onchange="priceRoute(this);">
                								
        <option value="AM-1">AM-1</option>
        <option value="AM-2">AM-2</option>
        <option value="AM-3">AM-3</option>
        <option value="AM-4">AM-4</option>
        <option value="AM-5">AM-5</option>
                								  
</select>

<select name="listingtypeAantalvluchten" id="listingtypeAantalvluchten" onchange="priceRoute(this);">

    <option value="1vlucht">1 vlucht</option>
    <option value="2vluchten">2 vluchten</option>
    <option value="3 vluchten">3 vluchten</option>
    <option value="4 vluchten">4 vluchten</option>
    <option value="5 vluchten">5 vluchten</option>
    <option value="6 vluchten">6 vluchten</option>
    <option value="7 vluchten">7 vluchten</option>
        								  
</select>

Answer 1

我会以几种方式更改您的代码。请在评论中要求澄清:

function priceRoute() {
    // PRIJZEN
    if (document.getElementById("listingtypeRouteAM").value == "AM-1" && document.getElementById("listingtypeAantalvluchten").value == "1vlucht" ){
        document.getElementById("innerHtml_div").innerHTML = "whatever you want here";          
    } else {
        document.getElementById("innerHtml_div").innerHTML = ""; 
    }
}

<select name="listingtypeRouteAM" id="listingtypeRouteAM" onchange="priceRoute();">
    <option selected disabled>Please select an option</option>
    <option value="AM-1">AM-1</option>
    <option value="AM-2">AM-2</option>
    <option value="AM-3">AM-3</option>
    <option value="AM-4">AM-4</option>
    <option value="AM-5">AM-5</option>
</select>

<select name="listingtypeAantalvluchten" id="listingtypeAantalvluchten" onchange="priceRoute();">
  <option selected disabled>Please select an option</option>
  <option value="1vlucht">1 vlucht</option>
  <option value="2vluchten">2 vluchten</option>
  <option value="3 vluchten">3 vluchten</option>
  <option value="4 vluchten">4 vluchten</option>
  <option value="5 vluchten">5 vluchten</option>
  <option value="6 vluchten">6 vluchten</option>
  <option value="7 vluchten">7 vluchten</option>
</select>

<div id="innerHtml_div"></div>