Comparing two arrays and showing diffs

otnb-injad

I have two arrays that I would like to show side-by-side showing the likenesses and differences. (Basically I want a sql full outer join on two arrays)

The arrays are almost identical but array1 could have values array2 does not and vice versa.

I have seen how array_diff shows only the diffs but I want to list all values of array1 next to array2 and when either side is deficient put a blank space so the arrays will be equal in length.

Hope this makes sense.

ex:
array1 contains 1,2,4,6,8
array2 contains 1,2,3,5,8

The results to the user would be: (underscores are to preserve formatting)

arr1arr2
11
22
3
4
_5

6
8___8

LordShryku

Provided they will be the same count...

<table border="0">
<?
$ar = array("1","2","3","4","8");
$br = array("1","2","4","6","8");

for($i=0;$i<count($ar);$i++) {
   echo "<tr>";
   if($ar[$i] != $br[$i]) {
      echo "<td>&nbsp;
            <td>".$br[$i]."
            <tr>
            <td>".$ar[$i]."
            <td>&nbsp;";
   }
   else {
      echo "<td>".$ar[$i]."
            <td>".$br[$i];
   }
}
?>
</table>

otnb-injad

If the count was different could the same logic still be applied.

LordShryku

With a couple small changes to find the bigger array, yeah

jwright

What small changes would complete this and show the differences on each side.(assuming the count will be different between the arrays)

The issue of finding the count of the array can be easily accomplished with the count function, but how does that play into showing the mismatches when each side can be deficient.

jwright

Assuming LordShryku's example:

<table border="0">
<?php
$ar = array("1","2","3","4","8");
$br = array("1","2","4","6","8");

for($i=0;$i<count($ar);$i++) {
echo "<tr>";
if($ar[$i] != $br[$i]) {
echo "<td> 
<td>".$br[$i]."
<tr>
<td>".$ar[$i]."
<td> ";
}
else {
echo "<td>".$ar[$i]."
<td>".$br[$i];
}
}
?>
</table>

what would need to be adapted if:
$ar was now $ar = array("1","2","3","4","8","10");
and $br was now $br = array("1","2","4","6","8","11","12");

I hope this makes sense.

HalfaBee

Replace
for($i=0;$i<count($ar);$i++) {

with

$c = max( count($ar),count($br);
for($i=0;$i<$c;$i++) {

HalfaBee

drawmack

<?php
$ar_1 = array(1,3,5,7,9):
$ar_2 = array(2,3,4,8);
$ar_3 = array_diff($ar_1,$ar_2);

for($i=0;$i<count($ar_3);$i++) 
{
    echo "\$ar_3['" . $i . "'] = " . $ar_3[$i] . "<br />\n";
} //end for
?>

http://www.php.net/array_diff

tekky

ohh ohh my turn!

<?
$ar = array(1, 2, 3, 4);
$br = array(3, 2, 1, 4, 5);

echo "<table border=1><tr><td>ar</td><td>br</td></tr>\n";
for($i=0;$i<max(count($ar), count($br));$i++)
{
	if ($ar[$i] === $br[$i])
	{
		echo '<tr><td>' . $ar[$i] . '</td><td>' . $br[$i] . "</td></tr>\n";
	}
	else
	{
		if (!empty($ar[$i]))
			echo '<tr><td>' . $ar[$i] . "</td><td>&amp;nbsp;</td></tr>\n";
		if (!empty($br[$i]))
			echo '<tr><td>&amp;nbsp;</td><td>' . $br[$i] . "</td></tr>\n";
	}
}
echo "</table>\n";
?>

it works... tested it 🙂
basically just combined the ideas in the thread and didnt use array_diff like you didnt want 😉

[edit - fixed it to stop displaying double tr's once it passed the smaller arrays bounds --]

bad76

Originally posted by tekky
ohh ohh my turn!

me too! me too! 🙂

 
$ar = array(1, 2, 6, 4); 
$br = array(3, 7, 1, 4, 5,9,12); 

echo "<table border=1><tr><td>ar</td>";
echo "<td>br</td></tr>\n"; 

sort($ar); sort($br); $i=0; $j=0; 
while( ($i<count($ar)) && ($j<count($br)) )
{
  if($ar[$i]==$br[$j])
  { 
    echo '<tr><td>' . $ar[$i] . '</td>';
    echo '<td>' . $br[$j] . '</td></tr>'; 
    $i++; $j++;
  } else if($ar[$i]<$br[$j]) {		
    echo '<tr><td>' . $ar[$i] . '</td>';
    echo '<td>&nbsp;</td></tr>'; 
    $i++;
  } else if($ar[$i]>$br[$j]) {
    echo '<tr><td>&nbsp;</td>';
    echo '<td>' . $br[$j] . '</td></tr>'; 
    $j++;
  }
}
while($i<count($ar))
{
  echo '<tr><td>' . $ar[$i] . '</td>';
  echo '<td>&nbsp;</td></tr>'; 
  $i++;
}
while($j<count($br)) 
{
  echo '<tr><td>&nbsp;</td>';
  echo '<td>' . $br[$j] . '</td></tr>'; 
  $j++;
}
echo "</table>";
?>

tekky

I dont think sorting was something he wanted... or for the values to flip flop since he labled the top of each column ar/br :p

bad76

Originally posted by tekky
I dont think sorting was something he wanted... or for the values to flip flop since he labled the top of each column ar/br :p

It was strongest of me! It's the "Contest" soul, I think... 🙂
This is a really good "Code Contest" thread!

Without sorting you need to do a n*n compares...
(for example...

for($i=0; $i<count($ar); $i++)
  if(in_array($ar[$i],$br))
  {
    echo '<tr><td>' . $ar[$i] . '</td>'; 
    echo '<td>' . $ar[$i] . '</td></tr>';  

  } else {
    echo '<tr><td>' . $ar[$i] . '</td>'; 
    echo '<td>&nbsp;</td></tr>';  

  }
for($i=0; $i<count($br); $i++)
  if(!in_array($br[$i],$ar))
  {
    echo '<tr><td>&nbsp;</td>'; 
    echo '<td>' . $br[$i] . '</td></tr>';  

  }

...)

Instead, with a custom sorting you can do it in n*log(n) compares, I think. I think I will try next... 😃

bye bye

(what about flip flop 😕 ?)

tekky

woops in reading the ar < br part I thought you were outputting the lowest value one first like 1 4 even if ar was 4 and br was 1... woops 🙂

and by the sound of his question he wanted to compare like array keys to like array keys... maybe I mis understand him :p

HalfaBee

How about this.

<?
$ar = array(1, 2, 6, 4);
$br = array(3, 7, 1, 4, 5,9,12);

echo "<table border=1><tr><td>ar</td>";
echo "<td>br</td></tr>\n";

sort( $ar );
reset( $ar );
sort( $br );
reset( $br );
$av = current( $ar );
$bv = current( $br );

while( $av AND $bv ) {
  if($av==$bv) {
      echo '<tr><td>' . $av . '</td>';
      echo '<td>' . $bv . '</td></tr>';
      $av = next( $ar );
      $bv = next( $br );
  } else if($av<$bv) {
      echo '<tr><td>' . $av . '</td>';
      echo '<td>&nbsp;</td></tr>';
      $av = next( $ar );
  } else if($av>$bv) {
      echo '<tr><td>&nbsp;</td>';
      echo '<td>' . $bv . '</td></tr>';
      $bv = next( $br );
  }
}
echo "</table>";
?>

HalfaBee

PHPGuru2

I had a problem with a multi-dimentional array, but I just found a solution for it. Maybe my function will help you solving your problem too.

http://www.phpbuilder.com/board/showthread.php?s=&threadid=10259540

bad76

Originally posted by HalfaBee
How about this.

Great. This version show even the number when count() are diff.

<?
$ar = array(1, 2, 6, 4);
$br = array(3, 7, 1, 4, 5,9,12);

echo "<table border=1><tr><td>ar</td>";
echo "<td>br</td></tr>\n";

sort($ar); reset($ar); sort($br); reset($br);
$av = current( $ar ); $bv = current( $br );

while( $av OR $bv ) {
  if($av==$bv) {
    $ap = $av; $bp = $bv;
    $av = next( $ar ); $bv = next( $br );
  } else if(($av)&&(($av<$bv) || !($bv))) {
    $ap = $av; $bp = "&nbsp;";
    $av = next( $ar );
  } else if(($bv)&&(($av>$bv)|| !($av))) {
    $ap = "&nbsp;"; $bp = $bv;
    $bv = next( $br );
  }
  echo '<tr><td>' . $ap . '</td>';
  echo '<td>' . $bp . '</td></tr>';
}
echo "</table>";
?>

jwright

wow!!!!!

This thread is getting good.

You guys have accomplished what I was trying to do, and you did it in several different ways.

I did not consider sorting when I first posted, but that does have an added value for me.

I appreciate you guys work, and will be digging through everything you have done.

thank you