comparing two arrays

[rahjiggah]

Hello

I have two arrays of mysql values $a1, $b1

I am trying to loop through each $a value, no problem,

but I want to see if each element in $a = one of the values in $b

so:

$a = array(1, 2, 3, 4, 5, 6);
$b = array(4, 6);
$y = '';
foreach ($a1 as $a){
 foreach ($b1 as $b){
  if ($a[val] == $b[val]){
  $y = '*';
  }
}
echo $y.$a.'<br />';
}  

I was kinna hoping it would give me

1

2

3

*4

5

*6

Its most definitely not though... Im sure Im flawed in my logic but have coded so much other crap I just can't see the answer! 

ty for the look/help.

 

[Ch0cu3r]

Rather have the second foreach use in_array to check to see if the current value is in the second array. Example

foreach($a as $aVal)
{
   if(in_array($aVal, $b))
      echo "*";

   echo "$aVal<br />";
}

[rahjiggah]

hmmmm ya I tried that one as well, didnt work

Here is the actual array via print_r

$uc_sid = Array ( [0] => Array ( [sid] => 11 [0] => 11 ) [1] => Array ( [sid] => 12 [0] => 12 ) )

$sectors = Array ( [0] => Array ( [sid] => 10 [0] => 10 [sSector] => Pharma [1] => Pharma ) [1] => Array ( [sid] => 11 [0] => 11 [sSector] => Energy [1] => Energy ) [2] => Array ( [sid] => 12 [0] => 12 [sSector] => Mining [1] => Mining ) [3] => Array ( [sid] => 13 [0] => 13 [sSector] => Special Situations [1] => Special Situations ) [4] => Array ( [sid] => 14 [0] => 14 [sSector] => Technology [1] => Technology ) )

foreach ($sectors as $s){

  if(in_array($s[sid], $uc_sid)){
	$y='*';

   }
  echo $y.$s[sid].'<br />';

   } 

just gives me:

10
11
12
13
14

[ginerjm]

Why did you show us two simple one dimensional arrays and ask for help with them?  Your latest post shows you are using two multi-dimensional arrays so OF COURSE the solution presented didn't work.

 

Rather silly of you to waste people's time, isn't it?

[Ch0cu3r]

Yea it does help if you showed your actual array structure when you posted orginally

 

But anyway. If are using PHP5.5 or greater you could use

$uc_sids = array_column($uc_sid, 'sid');
foreach ($sectors as $sector)
{
    $y = in_array($sector['sid'], $uc_sids) ? '*' : '';
    echo $y.$sector['sid'].'<br />';
}

Otherwise you'd need to do something like

foreach ($sectors as $sector)
{
    $y = ''; // reset $y to empty string for each value
    foreach($uc_sid as $uc)
    {
        if($sector['sid'] == $uc['sid'])
            $y = '*';
    }

    echo $y.$sector['sid'].'<br />';
}

[Barand]

Also:

 

firstly, you could have simplified your arrays by using xxx_fetch_assoc() or xxx_fetch_row. By using xxx_fetch_array()  you get the values twice.

 

second, you could probably have done the matching with your query instead of having to create the two arrays.

[Psycho]

second, you could probably have done the matching with your query instead of having to create the two arrays.

 

Yeah, but that would have probably required a JOIN!

[rahjiggah]

Great, thanks for the help, and the snarky answers  I prefaced this whole thing at the top... so go ahead and give'r Im so tired and batsh!t crazy right now its all good.

 

Again thanks for taking the time to answer the question.

[Frank_b]

The whole point is that the results from the database (if we are talking about multiple records) are stored in two dimensional arrays. Therefor you are not able to simply use 'in_array()' .

This will do:

foreach($sectors as $sector)
{
  foreach($uc_sid as $uc)
  {
    if($sector['sid'] == $uc['sid'])
    {
      echo 'found: ' . $sector['sid'] . '<br>';
    }
  }
}

Edited September 27, 2014 by Frank_b

[rahjiggah]

foreach ($sectors as $sector)
{
    $y = ''; // reset $y to empty string for each value
    foreach($uc_sid as $uc)
    {
        if($sector['sid'] == $uc['sid'])
            $y = '*';
    }

    echo $y.$sector['sid'].'<br />';
}

This did it, and was what I had before I asked, Im an idiot, it didnt work because I was declaring $y=''; outside the code block! thank you guys....

[mac_gyver]

if you do this using php code, rather than in the query, i would either fetch or convert the $uc_sid values to a one dimensional array of values before the start of the loop (it could contain a substantial number of values, up to and including the entire $sectors array), rather than to repeatedly loop over it inside of another loop.

[rahjiggah]

Ya I really couldnt figure out a way to do this with the sql query to be honest, I know that would be a more efficient way to do this

 

its for editing choices in a form, there are 5 sectors, so query 1 calls the sector_id and name from that table, query 2 calls the persons choices from the choice table.

 

then I just display all the sectors and used the second foreach like Ch0cu3r showed, but it would check all the sector boxes, It was because I was declaring $y=''; outside the first foreach block leaving meaning if it hit a match it was just showing checked for all.

Edited September 27, 2014 by rahjiggah

[Barand]

The query would look like this.

$sql = "SELECT 
        s.sector_id
        s.sector_name
        c.person_id
        FROM sector s
            LEFT JOIN choice c 
            ON s.sector_id = c.sector_id AND c.person_id = $person";

Where person_id has a value (ie not null) then that person has chosen the sector

[rahjiggah]

The query would look like this.

$sql = "SELECT 
        s.sector_id
        s.sector_name
        c.person_id
        FROM sector s
            LEFT JOIN choice c 
            ON s.sector_id = c.sector_id AND c.person_id = $person";

Where person_id has a value (ie not null) then that person has chosen the sector

Awesome! Just use the join, I get it now, thanx.