Question

我想要创建一个下拉菜单，该菜单会根据所选值生成另一个下拉菜单例如，如果选择美国从第一次下降然后第二次下拉包含美国的状态。我做了很多工作。我更喜欢使用javascript并使用数组

var country_arr = new Array("USA", "Singapore", "Pakistan")
var s_a = new Array();
s_a[0]="";
s_a[1]="CA|NJ|NY";
s_a[2]="paas|naas|taas";
s_a[3]="Islamabad|karachi|lahore";

但我也希望选择国家和州的“名称”，以便发送到mysql数据库。我想我必须使用双维数组。但是这次无法编码并且非常需要你的帮助。

Answer 1

<!DOCTYPE html>
<html>
<head>
    <title></title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <script type="text/javascript">
        var citiesByState = {
            USA: ["NY","NJ"],
            Singapore: ["taas","naas"]
        }
        function makeSubmenu(value) {
            if(value.length==0) document.getElementById("citySelect").innerHTML = "<option></option>";
            else {
                var citiesOptions = "";
                for(cityId in citiesByState[value]) {
                    citiesOptions+="<option>"+citiesByState[value][cityId]+"</option>";
                }
                document.getElementById("citySelect").innerHTML = citiesOptions;
            }
        }
        function displaySelected() {
            var country = document.getElementById("countrySelect").value;
            var city = document.getElementById("citySelect").value;
            alert(country+"\n"+city);
        }
        function resetSelection() {
            document.getElementById("countrySelect").selectedIndex = 0;
            document.getElementById("citySelect").selectedIndex = 0;
        }
    </script>
</head>
<body onload="resetSelection()">
    <select id="countrySelect" size="1" onchange="makeSubmenu(this.value)">
        <option></option>
        <option>USA</option>
        <option>Singapore</option>
    </select>
    <select id="citySelect" size="1">
        <option></option>
    </select>
    <button onclick="displaySelected()">show selected</button>
</body>
</html>

下拉菜单选择国家然后说明

1 个答案: