Displying Multiple Arrays Data - php

Question

I am displaying the list of users in the select box. There are two types of users i-e selected users and non selected users. The values of these users are coming from the database in two arrays i-e One array contains selected users record and other array contains all users record. Now i want if the page loads the selected users record should be shown as selected in the select box and non selected users will be shown as non selected. Here is my code:
if ($selected != false ){
foreach ($selected as $select)
{}
foreach ($data as $rows) { echo $rows->id."<br />"; echo $select->id; ?>
<option value="<?php echo $rows->id; ?>" <?php if ($rows->id == $select->id) echo "selected";?>><?php echo $rows->username; ?></option>
<?php } } else{
foreach ($data as $rows) ?>
<option value="<?php echo $rows->id; ?>" <?php if ($rows->id == $select->id) ?>><?php echo $rows->username; ?></option>
<?php } ?>
The $selected object contains the selected users list and the $data object contains non selected/total number of users

Answer 1

If i am not wrong you have two array like
$arr1 = array(array('id'=>1,"name"=>'abc1',"user"=>'select'),array('id'=>2,"name"=>'abc2',"user"=>'select'),array('id'=>3,"name"=>'abc3',"user"=>'select'),array('id'=>4,"name"=>'abc4',"user"=>'select'),array('id'=>5,"name"=>'abc5',"user"=>'select'),array('id'=>6,"name"=>'abc6',"user"=>'select'),array('id'=>7,"name"=>'abc7',"user"=>'select'));
$arr2 = array(array('id'=>8,"name"=>'abc8',"user"=>'noselect'),array('id'=>9,"name"=>'abc9',"user"=>'noselect'),array('id'=>10,"name"=>'abc10',"user"=>'noselect'),array('id'=>11,"name"=>'abc11',"user"=>'noselect'),array('id'=>12,"name"=>'abc12',"user"=>'noselect'),array('id'=>13,"name"=>'abc13',"user"=>'noselect'),array('id'=>14,"name"=>'abc14',"user"=>'noselect'));
$arraymerege = array_merge($arr1,$arr2); // Merge the array into one
check out the html it display the user selected. i'll just put the condition under select box if user is noselect then it show selected. Please check the image for loop

Answer 2

you are closing your first foreach before you actually get inside the loop...try this. (rewritten with a little shortcode added)
<select name="users" type="multiple">
<?php
//no need to write $selected == false,
//this is the same, a ! will compare this var to false
//also i use : instead because its much nicer to read i.m.o
//its also a little easier to tell the difference from a closing
//if and foreach this way if you have a lot of nested comparisons.
if (!$selected) :
//you want to loop through all rows first.
foreach ($data as $rows) :
//now look at each selected user per user
foreach ($selected as $select) : ?>
//here is where you make the comparison. no need for any other loops
//this is called a turnary comparison. its basically short code for
//if(blah) else this;
//read up on it here:
// http://www.php.net/manual/en/language.operators.comparison.php
//the <?= is the same as <?php echo. This does require for you to have
//short codes turned on in your main php.ini. It usually is though.
<option value="<?= $rows->id; ?>
<?= (($rows->id == $select->id) ? 'selected' :''); ?>
<?= $rows->username; ?>
</option>
endforeach;
endif;
?>
</select>
This is all the code you need. You should only require two loops. The very first loop would iterate through each user, and the nested loop would then compare each of those users to each selected user. Also, the ability to write cleaner code requires planning. I would suggest investing in a white board or a notepad to draw out flow charts, diagrams etc before you start writing your code. You will get a basic picture in your head. There are always 100 million ways to do one thing, but only one way that is right for you. And its up to you to find that way.

Answer 3

From how I read the question, he is showing all users and highlighting the selected ones in a multiple select box. He has multiple selected users so you couldn't merge the arrays together. You would have to compare each user in the table to each selected user then decide if you need to highlight that user or not.