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how to avoid repetition of values in dropdown list while updating in php

I want to update "profile of a user" in php. There is a repetition of one value for two times in dropdown list. for example i take language value='Punjabi' from database but there is also a value placed in dropdown with name of 'Punjabi'.
The issue is simply that there is a repetition of value which i don't want.
<?php $result=mysqli_query($conn, "select * from profile where id=$firstPerson");
while($queryArray=mysqli_fetch_array($result)){ ?>
<select name="language" id="language" >
<option value='<?php echo $queryArray["language"];?> '> <?php echo $queryArray["language"]; ?></option>
//for example, the value from database is "Punjabi"
<option value="Hindi">Hindi</option>
<option value="Punjabi">Punjabi</option>
<option value="Urdu">Urdu</option>
</select>
<?php } ?>
when a value='Punjabi' from database is selected in dropdown list, the dropdown should not show the value='Punjabi' that is already placed in dropdown.
Remember: i have more than 1000 values in my dropdown(html) list.
screenshot

Instead of creating a new option according to the user data, Check if existing options are equal to user data:
<select name="language" id="language" >
<option value="Punjabi" <?php if ($queryArray["language"]=="Punjabi"){echo 'selected="selected"'} ?>>Punjabi</option>
<option value="Hindi" <?php if ($queryArray["language"]=="Hindi"){echo 'selected="selected"'} ?>>Hindi</option>
<option value="Urdu" <?php if ($queryArray["language"]=="Urdu"){echo 'selected="selected"'} ?>>Urdu</option>
</select>
If there are large number of options and you don't want to hard code these conditions, you can remove the second option using javascript on DOM ready:
$(document).ready(function(){
$('option[value="<?php echo $queryArray["language"] ?>"]').eq(1).remove();
})

skip the loop when value is equal to Punjabi, Urdu and Hindi.
<?php $result=mysqli_query($conn, "select * from profile where id=$firstPerson");
while($queryArray=mysqli_fetch_array($result)){ ?>
<select name="language" id="language" >
<?php if($queryArray["language"]!="Punjabi" && $queryArray["language"]!="Urdu" &&
$queryArray["language"]!="Hindi") { ?>
<option value="Hindi">Hindi</option>
<option value="Punjabi">Punjabi</option>
<option value="Urdu">Urdu</option>
<?php } ?>

I think you are doing it wrong way the correct way would be having a table which stored all the languages along with values
using selected attribute to achieve your objective
<?php
$result=mysqli_query($conn, "select * from profile where id=$firstPerson");
$queryArray1=mysqli_fetch_array($result);
$langOfUser=$queryArray1["language"];
?>
<select name="language" id="language" >
<?php $result=mysqli_query($conn, "select * from langtab");
while($queryArray=mysqli_fetch_array($result)){ ?>
<option value='<?php echo $queryArray["languageValue"];?> ' <?php if($langOfUser== $queryArray["languageValue"]){ echo 'selected';}?>> <?php echo $queryArray["languageName"]; ?></option>
<?php } ?>
</select>

You have to use if condition to display values in select option.
<select name="language" id="language" >
<?php $result=mysqli_query($conn, "select * from profile where id=$firstPerson");
while($queryArray=mysqli_fetch_array($result)){
if($queryArray["language"]!="Punjabi") {
$opval = "<option value=" . $queryArray["language"] . ">". $queryArray["language"]. " </option> "
echo $opval;
}
?>
<option value="Punjabi">Punjabi</option>
<option value="Hindi">Hindi</option>
<option value="Urdu">Urdu</option>
</select>

So your problem is that you have html hardcoded options and database options. You need to merge them into one on that website.
So you can use some javascript
elements = [1, 2, 9, 15].join(',')
$.post('post.php', {elements: elements})
But you can fill your elements like this is you don´t want to write it by hand
$("#id select").each(function()
{
allOptionsInSelect.push($(this).val());
});
Than on php side you can do
$elements = $_POST['elements'];
$elements = explode(',', $elements);
And now you have html hardcoded select on server side. Now you need to check if it doesn´t already exist when you are printing from database
You can do that like this
if(in_array(value_from_database, $elements) {
// It is so skip
} else {
// It is not, so print it
}

You can use if elseif this way.
<select name="language" id="language" >
<option value='<?php echo $queryArray["language"];?>'><?php echo $queryArray["language"]; ?></option>
<?php if ($queryArray["language"] == "Hindi") { ?>
<option value="Punjabi">Punjabi</option>
<option value="Urdu">Urdu</option>
<?php } elseif ($queryArray["language"] == "Urdu") { ?>
<option value="Punjabi">Punjabi</option>
<option value="Hindi">Hindi</option>
<?php } elseif ($queryArray["language"] == "Punjabi") { ?>
<option value="Urdu">Urdu</option>
<option value="Hindi">Hindi</option>
<?php } ?>

How to change a second select list based on the first select list option when values are dynamic?

I have php page for vehicle search filter which have 2 types of vehicle that is RV's and campervans and also have two selects
<div class="fields">
<p>Vehicle Type</p>
<select class="car" name="car_type" id="car_type">
<option value="0">Select Vehicle</option>
<?php if(count($vehicleType) > 0 ){
foreach($vehicleType as $vt){ ?>
<option value="<?php echo $vt ?>" <?=isset($_GET['car_type'])&&$_GET['car_type']==$vt?'selected':'';?> ><?php echo $vt ?></option>
<?php }
} ?>
</select>
</div>
<div class="fields">
<p>Total No. of Passengers*</p>
<select class="half" name="passengers" id="passengers">
<option>No. of Passengers</option>
<option <?php if(#$_REQUEST['passengers'] == 1){?>selected<?php }?>>1</option>
<option <?php if(#$_REQUEST['passengers'] == 2){?>selected<?php }?>>2</option>
<option <?php if(#$_REQUEST['passengers'] == 3){?>selected<?php } ?>>3</option>
<option <?php if(#$_REQUEST['passengers'] == 4){?>selected<?php }?>>4</option>
<option <?php if(#$_REQUEST['passengers'] == 5){?>selected<?php }?>>5</option>
<option <?php if(#$_REQUEST['passengers'] == 6){?>selected<?php }?>>6</option>
<option <?php if(#$_REQUEST['passengers'] == 7){?>selected<?php }?>>7</option>
<option <?php if(#$_REQUEST['passengers'] == 8){?>selected<?php }?>>8</option>
</select>
</div>
How do I do that with jQuery or php if I choose "Rv" in the first select? The second select would show me 8 passengers . If I choose Campervan in the first select, the second select would show me 5 passengers..

I would probably do something along these lines:
<?php
$number_of_passengers = 8;
if(!empty($_REQUEST['car_type'])) {
$number_of_passengers = $_REQUEST['car_type'] == 'Campervans' ? 5 : 8;
}
$passengers = 0;
if(!empty($_REQUEST['passengers'])){
$passengers = (int) $_REQUEST['passengers'];
}
?>
<select class="car" name="car_type" id="car_type">
<option value="0">Select Vehicle</option>
<option value="RV/Motorhome">RV/Motorhome</option>
<option value="Campervans">Campervans</option>
</select>
<select class="half" name="passengers" id="passengers">
<option>No. of Passengers</option>
<?php
for($i = 1; $i <= $number_of_passengers; $i++) {
?>
<option
<?php
if($i == $passengers) {
echo ' selected ';
}
?>
>
<?php echo $i ?>
</option>
<?php
}
?>
</select>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script>
$('#car_type').change(function() {
$("#passengers").children().removeAttr("selected");
if ($(this).val() === 'Campervans') {
$('#passengers option:nth-child(n+7)').hide();
} else {
$('#passengers option').show();
}
});
</script>
There are cleaner ways of doing this but this should serve to get the point across.
Few things to note about the PHP:
See how I check if the $_REQUEST key is available using empty - this avoids having to use # which is generally not a good idea.
I am using a loop to echo the options in the passenger select to avoid code repetition because typing that out 8 times is boring ;-)
Hope this helps!

yes you need to add javascript code for that.
insert below code in your page and check if this is what you want?
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script type="text/javascript">
$('.car').on('change', function(){
if($(this).val() === 'RV/Motorhome'){
$('.half').find('option').show()
}else if($(this).val() === 'Campervans'){
$('.half').find('option').slice(6).hide();
}
})
</script>

how to select a specific option when a condition exists

I want to select the specific option in drop down list when a condition is existed.I set the Session in php and if the combo box has the value of 1 , it will be shown the option with value 1. I mean if session is 1, select the option with value of 1, if session is 2, select the option with vlaue of 2, and so on... . I want to set automatically select(I see the changes) with session in php.
sth like blewo:
<select id="sel" >
<option value='1'>one</option>
<option value='2'>two</option>
<option value='3'>three</option>
</select>
<?php $_SESSION['num']='1'; ?>
<script>
//must be shown the option with value of `1`.
<script>

Try this .
<select id="sel" >
<option value='1'>one</option>
<option value='2'>two</option>
<option value='3'>three</option>
</select>
<?php $_SESSION['num']='1'; ?>
<script>
//set local variable value so that I don't have to do it for each of the following ways to do this.
var num = "<?php echo $_SESSION['num']; ?>";
//normal javascript
document.getElementById("sel").value = num;
//using jQuery
$("#sel").val(num);
<script>
Or this try vikingmaster's way

You don't necessarily need js to do this. You can simply use php since you're already grabbing the num from the session.
Easiest way to do it would be:
<select id="sel" >
<?php if($_SESSION['num'] == 1): ?>
<option value='1' selected>one</option>
<?php else: ?>
<option value='1'>one</option>
<?php endif; ?>
<option value='2'>two</option>
<option value='3'>three</option>
</select>
But if you want to use javascript(jQuery in particular here), you can do something like this:
<script>
$(document).ready(function(){
var num = <?php echo $_SESSION['num']; ?>;
$('#sel > option').each(function(){
if($(this).val() == num){
$(this).prop('selected', true);
}
});
});
</script>
Here's a fiddle.
There are a lot of ways to do this. This is what approach I would take, I'm sure others can provide just as viable or probably better answers.

Just set the value with the selected attribute
<select id="sel" >
<option value='1' selected>one</option>
<option value='2'>two</option>
<option value='3'>three</option>
</select>
<?php $_SESSION['num']='1'; ?>
<script>
//alternately, set it explicitly
var element = document.getElementById('sel');
element.value = 1;
<script>

<select id="sel" >
<option value='1' <?php if($_SESSION['num']=='1') echo "selected"; ?> >one</option>
<option value='2' <?php if($_SESSION['num']=='2') echo "selected"; ?> >two</option>
<option value='3' <?php if($_SESSION['num']=='3') echo "selected"; ?> >three</option>
</select>

PHP - Fetch value based on what is selected from option

<select class="selectpicker" name="mscr_type" id="mscr_type">
<?php $fpp_type = '';
foreach ($getmilestone_cr as $mscr_list) {
$description = $mscr_list['FIX_PRJ_DESC'];//fetch description
if ($fpp_type != $mscr_list['FIX_PRJ_TYPE']) {
if ($fpp_type != '') {
echo '</optgroup>';
}
if($mscr_list['FIX_PRJ_TYPE'] == 'MS'):
echo $fpp_label = "Milestone";
elseif($mscr_list['FIX_PRJ_TYPE'] == 'CR'):
echo $fpp_label = "Change Request(CR)";
endif;
echo '<optgroup label="'.$fpp_label.'">';
}
echo '<option value="'.$mscr_list['FIX_PRJ_TYPE'].'">'.htmlspecialchars($mscr_list['FIX_PRJ_NAME']).'</option>';
$fpp_type = $mscr_list['FIX_PRJ_TYPE'];
}
if ($fpp_type != '') {
echo '</optgroup>';
}
?>
</select>
The above code outputs:
<select class="selectpicker">
<optgroup label="Picnic">
<option value ="1">Mustard</option>
<option value ="2">Ketchup</option>
<option value ="3">Relish</option>
</optgroup>
<optgroup label="Camping">
<option value ="4">Tent</option>
<option value ="5">Flashlight</option>
<option value ="6">Toilet Paper</option>
</optgroup>
</select>
How could I fetch description based on what is selected from selected option. For example if Mustard is selected, then input value should be filled
with value 'Mustard is yellow in color'.
Tried using <select class="selectpicker" name="mscr_type" id="mscr_type" onchange="document.getElementById('mscr_description').value=this.options[this.selectedIndex].text"> but it fetches the name and not description.
<label for="name" class="label">Description</label>
<input type="text" disabled="" id="selectpicker_description" name="selectpicker_description" class="span3">

Add the description to the HTML using a data-XXX attribute:
echo '<option value="'.$mscr_list['FIX_PRJ_TYPE'].'" data-description="'.htmlspecialchars($description).'">'.htmlspecialchars($mscr_list['FIX_PRJ_NAME']).'</option>';
Then you can use
onchange="updateDescription(this)"
with the Javascript function:
function updateDescription(sel) {
var output = document.getElementById('mscr_description');
var desc = sel.options[sel.selectedIndex].getAttribute('data-description');
output.value = desc;
}

What is the best way to figure out which drop down menu item should be active?

I have a page where the user can edit their information. One of the ways for the user to input information is a drop down menu. I have the value already and I need to make that value the active selection on the drop down menu. I know the most straightfoward way of doing with a bunch of if statements:
if ($classVal == "Freshman") {
echo "
<select name='class'>
<option selected>Freshman</option>
<option>Sophomore</option>
<option>Junior</option>
<option>Senior</option>
</select>
";
} else if ($classVal == "Sophomore") {
echo "
<select name='class'>
<option>Freshman</option>
<option selected>Sophomore</option>
<option>Junior</option>
<option>Senior</option>
</select> </p>
";
} else if ($classVal == "Junior") { ... }
This way has worked for me but I was wondering if there was a better way of accomplishing this.

You can test var inline like this :
echo "
<select name='class'>
<option ".($classVal == "Freshman" ? "selected" : "").">Freshman</option>
<option ".($classVal == "Sophomore" ? "selected" : "").">Sophomore</option>
<option ".($classVal == "Junior" ? "selected" : "").">Junior</option>
<option ".($classVal == "Senior" ? "selected" : "").">Senior</option>
</select>
";

<?php
$options = array('Freshman','Sophomore','Junior','Senior');
?>
<select name='class'>
<?php foreach($options as $op):?>
<option<?php echo $classVal==$op?'selected':'';?>> <?php echo $op;?> </option>
<?php endforeach;?>
</select>