Display array_key from PHP array?

Question

Here I am Having an Issue:

I have two arrays like the following:

  $array1 = array('1','2','1','3','1');
  $array2 = array('1','2','3'); // Unique $array1 values

with array2 values i need all keys of an array1

Expected Output Is:

 1 => 0,2,4
 2 => 1
 3 => 3

here it indicates array2 value =>array1 keys

i have tried with array_search(1, $array1) it is displaying only one matching key............. — Siva G
– Siva G, Commented May 7, 2013 at 13:26

xdazz · Accepted Answer · 2013-05-07 13:29:15Z

10

Just use a loop:

$result = array();
foreach ($array1 as $index => $value) {
  $result[$value][] = $index;
}

answered May 7, 2013 at 13:29

xdazz

161k38 gold badges255 silver badges278 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

gen_Eric · Accepted Answer · 2013-05-07 13:40:53Z

1

If you pass array_keys a 2nd parameter, it'll give you all the keys with that value.

So, just loop through $array2 and get the keys from $array1.

$result = array();
foreach($array2 as $val){
    $result[$val] = array_keys($array1, $val);
}

answered May 7, 2013 at 13:40

gen_Eric

228k42 gold badges304 silver badges343 bronze badges

Comments

asim-ishaq · Accepted Answer · 2013-05-07 13:49:13Z

The following code will do the job. It will create a result array in which the attribute val will contain the value that is searched in array and keys attribute will be an array that contains the found keys. Based on your values following is an example:

$array1 =array('1','2','1','3','1');
$array2 =array('1','2','3');

$results = array();

foreach ($array2 as $key2=>$val2) {
    $result = array();
    foreach ($array1 as $key1=>$val1 ) {
        if ($val2 == $val1) {
            array_push($result,$key1);  
        }
    }
    array_push($results,array("val"=>$val2,keys=>$result ));
}

 echo json_encode($results);

The result will be:

[{"val":"1","keys":[0,2,4]},
 {"val":"2","keys":[1]},
 {"val":"3","keys":[3]}]

Collectives™ on Stack Overflow

Display array_key from PHP array?

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related