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Removing all values but the first from a drop down list using jQuery

开发者 https://www.devze.com 2023-03-20 16:45 出处:网络
if (questions[0]) { $(\"select[id$=ddlPollQuestions] > option\").remove(); $(\'#ddlPollQuestions\').append(\'<option value=\"\">Choose a question to compare to</option>\');
             if (questions[0]) {
                 $("select[id$=ddlPollQuestions] > option").remove();
                 $('#ddlPollQuestions').append('<option value="">Choose a question to compare to</option>');
                 $.each(questions, function(i, question) {
                     $('#ddlPollQuestions').append('<option value="' + question.QUESTIONID + '">' + question.TEXT 开发者_如何转开发+ '</option>');
                 });
             } else {
                 $("select[id$=ddlPollQuestions] > option").remove();
                 $('#ddlPollQuestions').append('<option value="' + 0 + '">' + 'There are no questions of this type' + '</option>');
             }

What this does is it removes all the previous values, But i want my first option, which is "Choose a question ..." to remain, and then display "There are not questions..." as my 2nd option. My code here does not show "Choose a question.." as the first option. Thanks for having a look!


An easier approach:

$('#ddlPollQuestions').children('option:not(:first)').remove();


Use :gt selector.

Try this(Note that I have added a string variable to append the options after the each loop for better performance):

if (questions[0]) {
         $("select[id$=ddlPollQuestions] > option:gt(0)").remove();
         $('#ddlPollQuestions').append('<option value="">Choose a question to compare to</option>');
         var options = "";
         $.each(questions, function(i, question) {
            options += '<option value="' + question.QUESTIONID + '">' + question.TEXT + '</option>';
         });
         $('#ddlPollQuestions').append(options);
 } else {
         $("select[id$=ddlPollQuestions] > option:gt(0)").remove();
         $('#ddlPollQuestions').append('<option value="' + 0 + '">' + 'There are no questions of this type' + '</option>');
 }


since you are removing all the options in your code, you'll might just want to append again the Choose a question... in your else statement

if (questions[0]) {
    $("select[id$=ddlPollQuestions] > option").remove();
    $('#ddlPollQuestions').append('<option value="">Choose a question to compare to</option>');
    $.each(questions, function(i, question) {
        $('#ddlPollQuestions').append('<option value="' + question.QUESTIONID + '">' + question.TEXT + '</option>');
    });
} else {
    $("select[id$=ddlPollQuestions] > option").remove();
    $('#ddlPollQuestions').append('<option value="">Choose a question to compare to</option>');
    $('#ddlPollQuestions').append('<option value="' + 0 + '">' + 'There are no questions of this type' + '</option>');
}


example: http://jsfiddle.net/xeYwv/2/

var $PollQuestions = $('#ddlPollQuestions');

if (questions[0]) {
    $PollQuestions.children().remove();
    $PollQuestions.append('<option value="0">Choose a question to compare to</option>');
    $.each(questions, function(i, question) {
        $PollQuestions.append('<option value="' + question.QUESTIONID + '">' + question.TEXT + '</option>');
    });
} else {
    $PollQuestions.children().remove();
    $PollQuestions.append('<option value="' + 0 + '">' + 'There are no questions of this type' + '</option>');
}

what you had is already pretty close.

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