Question

我有一个表单，我需要根据用户从名为country的选择框中选择的内容来填写名为county（来自数组）的选择框的选项（例如，用户在国家/地区框中选择GB并且county box填充了数组中所有GB县的选项。我填写了选择框中的代码，但为数组中的每个值添加了一个选项（一个空值用于值不匹配的位置，另一个用于填充它们匹配的位置。这是一个很大的问题，因为我我的数组中有超过4000个项目，但只想返回一些结果。这是数组中的前50个项目：

ISO_3316_2[0][0] = "AF";
ISO_3316_2[0][1] = "AF-BDS";
ISO_3316_2[0][2] = "Badakhshan";
ISO_3316_2[1][0] = "AF";
ISO_3316_2[1][1] = "AF-BDG";
ISO_3316_2[1][2] = "Badghis";
ISO_3316_2[2][0] = "AF";
ISO_3316_2[2][1] = "AF-BGL";
ISO_3316_2[2][2] = "Baghlan";
ISO_3316_2[3][0] = "AF";
ISO_3316_2[3][1] = "AF-BAL";
ISO_3316_2[3][2] = "Balkh";
ISO_3316_2[4][0] = "AF";
ISO_3316_2[4][1] = "AF-BAM";
ISO_3316_2[4][2] = "Bamian";
ISO_3316_2[5][0] = "AF";
ISO_3316_2[5][1] = "AF-DAY";
ISO_3316_2[5][2] = "Daykondi";
ISO_3316_2[6][0] = "AF";
ISO_3316_2[6][1] = "AF-FRA";
ISO_3316_2[6][2] = "Farah";
ISO_3316_2[7][0] = "AF";
ISO_3316_2[7][1] = "AF-FYB";
ISO_3316_2[7][2] = "Faryab";
ISO_3316_2[8][0] = "AF";
ISO_3316_2[8][1] = "AF-GHA";
ISO_3316_2[8][2] = "Ghazni";
ISO_3316_2[9][0] = "AF";
ISO_3316_2[9][1] = "AF-GHO";
ISO_3316_2[9][2] = "Ghowr";
ISO_3316_2[10][0] = "AF";
ISO_3316_2[10][1] = "AF-HEL";
ISO_3316_2[10][2] = "Helmand";
ISO_3316_2[11][0] = "AF";
ISO_3316_2[11][1] = "AF-HER";
ISO_3316_2[11][2] = "Herat";
ISO_3316_2[12][0] = "AF";
ISO_3316_2[12][1] = "AF-JOW";
ISO_3316_2[12][2] = "Jowzjan";
ISO_3316_2[13][0] = "AF";
ISO_3316_2[13][1] = "AF-KAB";
ISO_3316_2[13][2] = "Kabul [Kabol]";
ISO_3316_2[14][0] = "AF";
ISO_3316_2[14][1] = "AF-KAN";
ISO_3316_2[14][2] = "Kandahar";
ISO_3316_2[15][0] = "AF";
ISO_3316_2[15][1] = "AF-KAP";
ISO_3316_2[15][2] = "Kapisa";
ISO_3316_2[16][0] = "AF";
ISO_3316_2[16][1] = "AF-KHO";
ISO_3316_2[16][2] = "Khowst";
ISO_3316_2[17][0] = "AF";
ISO_3316_2[17][1] = "AF-KNR";
ISO_3316_2[17][2] = "Konar [Kunar]";
ISO_3316_2[18][0] = "AF";
ISO_3316_2[18][1] = "AF-KDZ";
ISO_3316_2[18][2] = "Kondoz [Kunduz]";
ISO_3316_2[19][0] = "AF";
ISO_3316_2[19][1] = "AF-LAG";
ISO_3316_2[19][2] = "Laghman";
ISO_3316_2[20][0] = "AF";
ISO_3316_2[20][1] = "AF-LOW";
ISO_3316_2[20][2] = "Lowgar";
ISO_3316_2[21][0] = "AF";
ISO_3316_2[21][1] = "AF-NAN";
ISO_3316_2[21][2] = "Nangrahar [Nangarhar]";
ISO_3316_2[22][0] = "AF";
ISO_3316_2[22][1] = "AF-NIM";
ISO_3316_2[22][2] = "Nimruz";
ISO_3316_2[23][0] = "AF";
ISO_3316_2[23][1] = "AF-NUR";
ISO_3316_2[23][2] = "Nurestan";
ISO_3316_2[24][0] = "AF";
ISO_3316_2[24][1] = "AF-ORU";
ISO_3316_2[24][2] = "Oruzgan [Uruzgan]";
ISO_3316_2[25][0] = "AF";
ISO_3316_2[25][1] = "AF-PIA";
ISO_3316_2[25][2] = "Paktia";
ISO_3316_2[26][0] = "AF";
ISO_3316_2[26][1] = "AF-PKA";
ISO_3316_2[26][2] = "Paktika";
ISO_3316_2[27][0] = "AF";
ISO_3316_2[27][1] = "AF-PAN";
ISO_3316_2[27][2] = "Panjshir";
ISO_3316_2[28][0] = "AF";
ISO_3316_2[28][1] = "AF-PAR";
ISO_3316_2[28][2] = "Parwan";
ISO_3316_2[29][0] = "AF";
ISO_3316_2[29][1] = "AF-SAM";
ISO_3316_2[29][2] = "Samangan";
ISO_3316_2[30][0] = "AF";
ISO_3316_2[30][1] = "AF-SAR";
ISO_3316_2[30][2] = "Sar-e Pol";
ISO_3316_2[31][0] = "AF";
ISO_3316_2[31][1] = "AF-TAK";
ISO_3316_2[31][2] = "Takhar";
ISO_3316_2[32][0] = "AF";
ISO_3316_2[32][1] = "AF-WAR";
ISO_3316_2[32][2] = "Wardak [Wardag]";
ISO_3316_2[33][0] = "AF";
ISO_3316_2[33][1] = "AF-ZAB";
ISO_3316_2[33][2] = "Zabol [Zabul]";
ISO_3316_2[34][0] = "AL";
ISO_3316_2[34][1] = "AL-BR";
ISO_3316_2[34][2] = "Berat";
ISO_3316_2[35][0] = "AL";
ISO_3316_2[35][1] = "AL-BU";
ISO_3316_2[35][2] = "Bulqiz";
ISO_3316_2[36][0] = "AL";
ISO_3316_2[36][1] = "AL-DL";
ISO_3316_2[36][2] = "Delvin";
ISO_3316_2[37][0] = "AL";
ISO_3316_2[37][1] = "AL-DV";
ISO_3316_2[37][2] = "Devoll";
ISO_3316_2[38][0] = "AL";
ISO_3316_2[38][1] = "AL-DI";
ISO_3316_2[38][2] = "Dib";
ISO_3316_2[39][0] = "AL";
ISO_3316_2[39][1] = "AL-DR";
ISO_3316_2[39][2] = "Durr";
ISO_3316_2[40][0] = "AL";
ISO_3316_2[40][1] = "AL-EL";
ISO_3316_2[40][2] = "Elbasan";
ISO_3316_2[41][0] = "AL";
ISO_3316_2[41][1] = "AL-FR";
ISO_3316_2[41][2] = "Fier";
ISO_3316_2[42][0] = "AL";
ISO_3316_2[42][1] = "AL-GJ";
ISO_3316_2[42][2] = "Gjirokast";
ISO_3316_2[43][0] = "AL";
ISO_3316_2[43][1] = "AL-GR";
ISO_3316_2[43][2] = "Gramsh";
ISO_3316_2[44][0] = "AL";
ISO_3316_2[44][1] = "AL-HA";
ISO_3316_2[44][2] = "Has";
ISO_3316_2[45][0] = "AL";
ISO_3316_2[45][1] = "AL-KA";
ISO_3316_2[45][2] = "Kavaj";
ISO_3316_2[46][0] = "AL";
ISO_3316_2[46][1] = "AL-ER";
ISO_3316_2[46][2] = "Kolonj";
ISO_3316_2[47][0] = "AL";
ISO_3316_2[47][1] = "AL-KO";
ISO_3316_2[47][2] = "Kor";
ISO_3316_2[48][0] = "AL";
ISO_3316_2[48][1] = "AL-KR";
ISO_3316_2[48][2] = "Kruj";
ISO_3316_2[49][0] = "AL";
ISO_3316_2[49][1] = "AL-KU";
ISO_3316_2[49][2] = "Kuk";

这是javascript函数：

function ISO3316CountyChange(country) {

    //Empty the options array
    document.test.county.options.length = 0;

    //For every item in the array
    for (i=0; i<ISO_3316_2.length; i++){

        //If the ISO 3316 alpha 2 value in the array matches the ISO 3316 alpha 2 value from the country select field
        if(ISO_3316_2[i][0] == country) {

            //Add an unselected option for the country with the ISO 3316-2 value as the value and the ISO 3316-2 name as the user visible value
            document.test.county.options[i]=new Option(ISO_3316_2[i][2], ISO_3316_2[i][1], false, false);

        };

    };

    //Add the default field
    document.test.county.options[i]=new Option("Please select a county/state", "", true, true); 
};

以下是表格：

<form name="test">

<select name="country" onChange="ISO3316CountyChange(this.value)">
    <option value="" selected="selected">Please select a country</option>
    <option value="AF">AF</option>
    <option value="GB">GB</option>
    <option value="US">US</option>
</select>

<select name="county">
    <option value="">Please select a country first</option>
</select>

使用数组代码段测试此功能的最简单方法是选择“AF”选项，因为此代码段包含阿富汗（AF）和阿尔巴尼亚（AL）的条目。

修改

谢谢Max，除了一个修改:)之外还有效。这是新功能：

//更改县选择框中的县功能ISO3316CountyChange（国家）{

//Empty the options array
document.test.county.options.length = 0;

//Add the default field
document.test.county.options[0]=new Option("Please select a county/state", "", true, true);

//Variable containing the index of next option you should use
var nextOptionNum = 1;

//For every item in the array
for (i=0; i<ISO_3316_2.length; i++){

    //If the ISO 3316 alpha 2 value in the array matches the ISO 3316 alpha 2 value from the country select field
    if(ISO_3316_2[i][0] == country) {

        //Add an unselected option for the country with the ISO 3316-2 value as the value and the ISO 3316-2 name as the user visible value using the index of the next option
        document.test.county.options[nextOptionNum]=new Option(ISO_3316_2[i][2], ISO_3316_2[i][1], false, false);
        nextOptionNum++; //Increase the index ONLY if you used it
    };

};

};

Answer 1

试试这个：

int nextOptionNum = 0; //Variable containing the index of next option you should use
//For every item in the array
for (i=0; i<ISO_3316_2.length; i++){

    //If the ISO 3316 alpha 2 value in the array matches the ISO 3316 alpha 2 value from the country select field
    if(ISO_3316_2[i][0] == country) {

        //Add an unselected option for the country with the ISO 3316-2 value as the value and the ISO 3316-2 name as the user visible value
        //Use the index of the next option
        document.test.county.options[nextOptionNum]=new Option(ISO_3316_2[i][2], ISO_3316_2[i][1], false, false);
        nextOptionNum++; //Increase the index ONLY if you used it
    };
};

使用某些数组项填充选择框

1 个答案: