Select dropdown value from variable - php

Question

I wanted to have a dropdown's selected value be determined by the results of the a query. But whatever I try, its selected value stays at the very first option.
I've browsed multiple questions with the same problem, but none solved my problem.
I've tried this:
<select name="Period">
<option value="Day" <?php if($PeriodTXT == "Day") echo "selected"?>>Day</option>
<option value="Week" <?php if($PeriodTXT == "Week") echo "selected"?>>Week</option>
<option value="Month" <?php if($PeriodTXT == "Month") echo "selected"?>>Month</option>
<option value="Year" <?php if($PeriodTXT == "Year") echo "selected"?>>Year</option>
</select>
And this:
<select name="Period">
<option <?php echo ($PeriodTXT == 'Day')?"selected":"" ?> >Day</option>
<option <?php echo ($PeriodTXT == 'Week')?"selected":"" ?> >Week</option>
<option <?php echo ($PeriodTXT == 'Month')?"selected":"" ?> >Month</option>
<option <?php echo ($PeriodTXT == 'Year')?"selected":"" ?> >Year</option>
</select>
But it won't work. Also when I use echo "$PeriodTXT"; it echos "Week" (exactly as written in the options of the dropdown), so it should've selected "Week" but it doesn't.
EDIT: $PeriodTXT is supposed to show the selected interval that came with a number count (example "3 Day" it would only keep the "Day" part)
$usersdata = array();
while($row = mysqli_fetch_array($result))
{
$usersdata = $row;
}
$PeriodTXT = preg_replace("/\d+/u", "", $usersdata[4]);

Answer 1

Your problem was extra whitespace around the text while you were removing count with regex, so hidden extra whitespace was yielding condition as false,
$PeriodTXT = '3 Week';
$PeriodTXT = preg_replace("/\d+/u", "", $usersdata[4]); //without trim()
var_dump($PeriodTXT); // outputs string ' Week' (length=5)
but when we trim it
$PeriodTXT = trim(preg_replace("/\d+/u", "", $usersdata[4])); //with trim()
var_dump($PeriodTXT); // outputs string 'Week' (length=4)
So use trim() to fix that, working eg,
<?php
$usersdata = array();
$usersdata[4] = '3 Week';
$PeriodTXT = trim(preg_replace("/\d+/u", "", $usersdata[4]));
?>
<select name="Period">
<option <?php echo ($PeriodTXT === 'Day')?"selected ='selected'":"" ?> >Day</option>
<option <?php echo ($PeriodTXT === 'Week')?"selected ='selected'":"" ?> >Week</option>
<option <?php echo ($PeriodTXT === 'Month')?"selected ='selected'":"" ?> >Month</option>
<option <?php echo ($PeriodTXT === 'Year')?"selected ='selected'":"" ?> >Year</option>
</select>
Also notice I have changed the HTML part from "selected":"" to "selected ='selected'":""

Answer 2

I understand you send a form using POST method, and after you send it, you would like to try display it with the selected option.
Please describe what is $PeriodTXT variable and how do you set it up.
Here is a solution to make it easy, hope it will help you.
$sent = $_POST['Period'];
$options = aray("Day", "Week", "Month", "Year");
echo '<form method="post" action="">
<select name="Period">';
foreach ($options as $v)
{
$selected = ($sent == $v) ? ' selected' : null;
echo '<option value="'.$v.'"'.$selected.'>'.$v.'</option>';
}
echo '</select>
<input type="submit" value="send">
</form>';
EDIT:
Code with "while" you have posted, seems to be wrong.
You are creating $userdata variable each time when while() goes. In fact it's not a real array, as you want it to be. It only works, when you select only one record from database (when mysql_num_rows($result) == 1). Otherwise it' wrong.
It should be done this way:
$usersdata = array();
while($row = mysqli_fetch_array($result))
{
$usersdata[] = $row;
}
$PeriodTXT = preg_replace("/\d+/u", "", $usersdata[$index][4]);
Notice, that you have to know which row ($index variable) you are doing changes in.
$usersdata becomes an Associative array.
Use var_dump() function to check what a variable contains itself. I hope it will get you closer to the solution. If you need more help, you have to post more code, because for now not everything is clear here.