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With 720 if() statements, you might want to consider a <a href="http://php.net/manual/en/control-structures.switch.php" rel="ugc">switch</a> construct. &nbsp;But seriously, please show us what you've tried and what kind of output you're getting. &nbsp;I am sure we can help.
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<div>
This might be one way of looking at the problem. 
 

<pre><code class="code-10 nolinks" id="code-20-39705028-1">&lt;?php // RAY_combinations_all_ordered_subsets.php
error_reporting(E_ALL);
echo &quot;&lt;pre&gt;&quot;;


// PROBLEM: FIND ALL ORDERED SUBSETS OF A CHARACTER SET
// EXAMPLE: IN &quot;ABC&quot; IT MUST FIND &quot;A&quot;, &quot;AB&quot;, &quot;BA&quot;, ETC.


// FUNCTION TO GENERATE THE COMBINATIONS OF CHARACTERS IN A STRING.
// OUTPUT IS AN ARRAY OF COUNT = strlen() FACTORIAL
// ADAPTED FROM http://cogo.wordpress.com/2008/01/08/string-permutation-in-php/
function string_combinations($str)
{
 if (strlen($str) &lt; 2) return array($str);

 $combos = array();
 $endpop = substr($str, 1);

 // RECURSE
 foreach (string_combinations($endpop) as $permutation)
 {
 $length = strlen($permutation);
 for ($i = 0; $i &lt;= $length; $i++)
 {
 $combos[] = substr($permutation, 0, $i) . $str[0] . substr($permutation, $i);
 }
 }
 return $combos;
}


// GENERATE THE COMBINATIONS OF ELEMENTS IN A ONE-DIMENSIONAL ARRAY
function array_combinations($arr)
{
 $return = array();

 // GET THE NUMERIC KEY RANGE OF THE INPUT ARRAY
 $str = implode('', range(0, count($arr)-1));

 // GET THE KEY COMBINATIONS
 $combos = string_combinations($str);

 // ITERATE OVER THE COMBINATIONS
 foreach ($combos as $combo)
 {
 $out = array();
 while (strlen($combo))
 {
 $key = substr($combo,0,1);
 $combo = substr($combo,1);
 $out[] = $arr[$key];
 }
 $ndx = implode(NULL, $out);
 $return[$ndx] = $out;
 }
 return $return;
}


// DEMONSTRATE THE CODE
$abc = 'ABCDEF';
$abc = str_split($abc);
$cnt = count($abc) - 1;

// GET ALL LARGEST COMBINATIONS IN ARRAY FORMAT
$out = array_combinations($abc);
$out = array_keys($out);

// REDUCE THE STRING LENGTHS TO FIND SMALLER COMBINATIONS
while ($cnt)
{
 foreach ($out as $key)
 {
 $key = substr($key, 0, $cnt);
 $key = str_split($key);
 sort($key);
 $key = implode(NULL, $key);
 $new[$key] = $key;
 }
 $cnt--;
}

// WITH EACH OF THE REDUCED STRINGS, ADD ALL COMBINATIONS
foreach ($new as $abc)
{
 $arr = array_combinations(str_split($abc));
 $out = array_merge($out, array_keys($arr));
}

// SHOW THE WORK PRODUCT
sort($out);
echo &quot;FOUND &quot; . number_format(count($out)) . &quot; COMBINATIONS&quot;;
echo PHP_EOL;
print_r($out);
</code></pre>
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<div>
&gt;&gt; if(1 and 2 and 3 and 4 and 5) &nbsp;{ &nbsp;do that &nbsp;} 
Just noticed this condition which is not the same as: 
&nbsp; &nbsp; &nbsp;if(1 and 2 and 3 and 4 and 5 and not 6) &nbsp;{ &nbsp;do that &nbsp;} 
 
Your previous examples always had 6 conditions in them, but this one has only 5. Is that your intent?
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<div>
Is this question related to coursework - homework or otherwise? If so, then you should provide us with what you have and ask a specific question about a problem since EE policy says that we provide guidance but not solutions to academic type questions.
</div>

<div>
&gt;&gt; The max number of combinations is 2^6 = 64, not 6! = 720 
Thanks for agreeing with me. But as I asked the author, if his last test of 

<div class="indent">
if(1 and 2 and 3 and 4 and 5) &nbsp;{ &nbsp;do that &nbsp;}
</div>
is really what he meant, then there are more than 64 combined conditions to consider.
</div>

<div>
Thanks for all your replies. This is far beyond what I had in mind. I appreciate your willingness to help. I want to Close this matter now.
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<div>
<div class="content wysiwyg-content">
Suppose we have six constants: 1 through 6. 
 
I would like to have a formula to get all combinations of of them, 
 
I give an example of what I mean: 
 
1 and 2 and 3 and 4 and 5 and 6 
1 and 2 and 3 and 4 and 5, but not 6 
1 and 2 and 3 and 4, but not 5 and 6 
... 
2 and 3 and 4 and 5 and 6, but not 1 
3 and 4 and 5 and 6, but not 1 and 2 
... 
1 and 3 and 4 and 5 and 6, but not 2 
1 and 4 and 5 and 6, but not 2 and 3 
... 
... 
I Think you've got it. 
 
Lastly, I'd put this in a php script to get the correct combination 
 
if(1 and 2 and 3 and 4 and 5 and 6) { &nbsp;do this &nbsp;} 
if(1 and 2 and 3 and 4 and 5) &nbsp;{ &nbsp;do that &nbsp;} 
 
For me this is far over my training. Could you please lead me thorugh this. 
 
Thanks.
</div>
</div>

Suppose we have six constants: 1 through 6.

I would like to have a formula to get all combinations of of them,

I give an example of what I mean:

1 and 2 and 3 and 4 and 5 and 6
1 and 2 and 3 and 4 and 5, but not 6
1 and 2 and 3 and 4, but not 5 and 6
...
2 and 3 and 4 and 5 and 6, but not 1
3 and 4 and 5 and 6, but not 1 and 2
...
1 and 3 and 4 and 5 and 6, but not 2
1 and 4 and 5 and 6, but not 2 and 3
...
...
I Think you've got it.

Lastly, I'd put this in a php script to get the correct combination

if(1 and 2 and 3 and 4 and 5 and 6) {  do this  }
if(1 and 2 and 3 and 4 and 5)  {  do that  }

For me this is far over my training. Could you please lead me thorugh this.

Thanks.

how do I get all combinations of a set of constants?

An algorithm is a self-contained step-by-step set of operations to be performed. Algorithms exist that perform calculation, data processing, and automated reasoning. Starting from an initial state and initial input (perhaps empty), the instructions describe a computation that, when executed, proceeds through a finite number of well-defined successive states, eventually producing "output" and terminating at a final ending state. The transition from one state to the next is not necessarily deterministic; some algorithms, known as randomized algorithms, incorporate random input.

Algorithms

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