how to combine an array

Question

array is like this : $arr = array("a","b","c","d");

I want to combine it. The result must have "abcd" and not repeat.

Example : $r = array("ab","cd") || array("a","bcd") || array("abcd") || array("ab","c","d")

Now I use the following function:

function combination(){  
$str = array("a","b","c","d");  
$result = array();  
$c = count($str);  
$nbin = 1 << $c;  
for($i = 1; $i < $nbin; $i++){  
        $element = "";  
        for($j=0;$j < $c; $j++){  
                if((1 << $j & $i) !=0 ){  
                        $element .= $str[$j];  
                }  
        }  
        array_push($result,$element);  
}  
        return $result;  
}

This is the $result:

Array
(
    [0] => a
    [1] => b
    [2] => ab
    [3] => c
    [4] => ac
    [5] => bc
    [6] => abc
    [7] => d
    [8] => ad
    [9] => bd
    [10] => abd
    [11] => cd
    [12] => acd
    [13] => bcd
    [14] => abcd
)

How should I do this?

What does this have to do with java or javascript? – shmosel Jan 17 '17 at 05:05 — shmosel, Jan 17 '17 at 05:05
implement this algorithm by js or java or php – xuzeng Jan 17 '17 at 05:11 — xuzeng, Jan 17 '17 at 05:11

score 0 · Answer 1 · answered Jan 17 '17 at 05:14

0

I'm a little uncertain what exactly you are expecting to be returned by your code. Assuming all you want returned is element 14 of your array (ONLY abcd), you can use the PHP function implode. This concatenates all the elements in the array together. i.e.,

$array = array('a', 'b', 'c', 'd');
var_dump(implode($array));
var_dump(implode('-', $array));

will return string 'abcd' and then string 'a-b-c-d'

I hope this answers what you were asking.

answered Jan 17 '17 at 05:14

Michael Thompson

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21

thanks,but i want to get some array. Each array include some element of $result. The array like array("a","bcd") or array("bc","ad"). duplicate character is no need. example: array("a","abc") – xuzeng Jan 17 '17 at 06:00
So what you would like is to get all different character combinations that fit into 2 array elements? – Michael Thompson Jan 17 '17 at 06:37
Could your question be solved by this answer? http://stackoverflow.com/questions/10834393 – Michael Thompson Jan 17 '17 at 08:39
Thank you for your answer sincerely. – xuzeng Jan 18 '17 at 01:24

how to combine an array

1 Answers1