How to implode array with key and value without foreach in PHP

You could use http_build_query, like this:

<?php
  $a=array("item1"=>"object1", "item2"=>"object2");
  echo http_build_query($a,'',', ');
?>

Output:

item1=object1, item2=object2 

Demo

I spent measurements (100000 iterations), what fastest way to glue an associative array?

Objective: To obtain a line of 1,000 items, in this format: "key:value,key2:value2"

We have array (for example):

$array = [
    'test0' => 344,
    'test1' => 235,
    'test2' => 876,
    ...
];

Test number one:

Use http_build_query and str_replace:

str_replace('=', ':', http_build_query($array, null, ','));

Average time to implode 1000 elements: 0.00012930955084904

Test number two:

Use array_map and implode:

implode(',', array_map(
        function ($v, $k) {
            return $k.':'.$v;
        },
        $array,
        array_keys($array)
    ));

Average time to implode 1000 elements: 0.0004890081976675

Test number three:

Use array_walk and implode:

array_walk($array,
        function (&$v, $k) {
            $v = $k.':'.$v;
        }
    );
implode(',', $array);

Average time to implode 1000 elements: 0.0003874126245348

Test number four:

Use foreach:

    $str = '';
    foreach($array as $key=>$item) {
        $str .= $key.':'.$item.',';
    }
    rtrim($str, ',');

Average time to implode 1000 elements: 0.00026632803902445

I can conclude that the best way to glue the array - use http_build_query and str_replace

I would use serialize() or json_encode().

While it won't give your the exact result string you want, it would be much easier to encode/store/retrieve/decode later on.

Using array_walk

$a = array("item1"=>"object1", "item2"=>"object2","item-n"=>"object-n");
$r=array();
array_walk($a, create_function('$b, $c', 'global $r; $r[]="$c=$b";'));
echo implode(', ', $r);

IDEONE

You could use PHP's array_reduce as well,

$a = ['Name' => 'Last Name'];

function acc($acc,$k)use($a){ return $acc .= $k.":".$a[$k].",";}

$imploded = array_reduce(array_keys($a), "acc");

Change

-    return substr($result, (-1 * strlen($glue)));
+    return substr($result, 0, -1 * strlen($glue));

if you want to resive the entire String without the last $glue

function key_implode(&$array, $glue) {
    $result = "";
    foreach ($array as $key => $value) {
        $result .= $key . "=" . $value . $glue;
    }
    return substr($result, (-1 * strlen($glue)));
}

And the usage:

$str = key_implode($yourArray, ",");

For debugging purposes. Recursive write an array of nested arrays to a string. Used foreach. Function stores National Language characters.

function q($input)
{
    $glue = ', ';
    $function = function ($v, $k) use (&$function, $glue) {
        if (is_array($v)) {
            $arr = [];
            foreach ($v as $key => $value) {
                $arr[] = $function($value, $key);
            }
            $result = "{" . implode($glue, $arr) . "}";
        } else {
            $result = sprintf("%s=\"%s\"", $k, var_export($v, true));
        }
        return $result;
    };
    return implode($glue, array_map($function, $input, array_keys($input))) . "\n";
}

Here is a simple example, using class:

$input = array(
    'element1'  => 'value1',
    'element2'  => 'value2',
    'element3' =>  'value3'
);

echo FlatData::flatArray($input,', ', '=');

class FlatData
{

    public static function flatArray(array $input = array(), $separator_elements = ', ', $separator = ': ')
    {
        $output = implode($separator_elements, array_map(
            function ($v, $k, $s) {
                return sprintf("%s{$s}%s", $k, $v);
            },
            $input,
            array_keys($input),
            array_fill(0, count($input), $separator)
        ));
      return $output;
    }

}

For create mysql where conditions from array

$sWheres = array('item1'  => 'object1',
                 'item2'  => 'object2',
                 'item3'  => 1,
                 'item4'  => array(4,5),
                 'item5'  => array('object3','object4'));
$sWhere = '';
if(!empty($sWheres)){
    $sWhereConditions = array();
    foreach ($sWheres as $key => $value){
        if(!empty($value)){
            if(is_array($value)){
                $value = array_filter($value); // For remove blank values from array
                if(!empty($value)){
                    array_walk($value, function(&$item){ $item = sprintf("'%s'", $item); }); // For make value string type 'string'
                    $sWhereConditions[] = sprintf("%s in (%s)", $key, implode(', ', $value));
                }
            }else{
                $sWhereConditions[] = sprintf("%s='%s'", $key, $value);
            }
        }
    }
    if(!empty($sWhereConditions)){
        $sWhere .= "(".implode(' AND ', $sWhereConditions).")";
    }
}
echo $sWhere;  // (item1='object1' AND item2='object2' AND item3='1' AND item4 in ('4', '5') AND item5 in ('object3', 'object4'))

Short one:

$string = implode('; ', array_map(fn($k, $v) => "$k=$v", array_keys($array), $array));

Using explode to get an array from any string is always OK, because array is an always in standard structure.

But about array to string, is there any reason to use predefined string in codes? while the string SHOULD be in any format to use!

The good point of foreach is that you can create the string AS YOU NEED IT! I'd suggest still using foreach quiet readable and clean.

$list = array('a'=>'1', 'b'=>'2', 'c'=>'3');

$sql_val = array();
foreach ($list as $key => $value) {
    $sql_val[] = "(" . $key . ", '" . $value . "') ";
}
$sql_val = implode(', ', $sql_val);

with results:

(a, '1') , (b, '2') , (c, '3') 

|

(a: '1') , (b: '2') , (c: '3') 

|

a:'1' , b:'2' , c:'3' 

etc.

I was looking for a solution to this question and I know it's been 10 years old but halfway the page, I thought: why not string replace on a json encode. It will give you easy access on how to configure the string. Also, it's a oneliner that avoids a (foreach) loop.

It would look something like this:

$wrapperAttributesString = str_replace(['{"' , '"}', '":', '","'],['' , '', '=', ' '], json_encode($wrapperAttributes));

So, bassically what happens here is:

$wrapperAttributes['class'] = 'hi__stack--overflow';
$wrapperAttributes['style'] = 'overflow: stack; ';
$wrapperAttributes['id']    = 'oneliner_array_with_keys_tostring_attributes';

//if we were to json encode this array: it would result in this:
// {"class":"hi__stack--overflow","style":"overflow: stack; ","id":"oneliner_array_with_keys_tostring_attributes"}

now the str_replace first argument takes an array with find what, the second is an array to replace that with. so it does:

find {" and replace with nothing;

find }" and replace with nothing;

find ": and replace with =;

find "," and replace with " ; to close the attribute and space to chain next

the output would be

class="hi__stack--overflow" style="overflow: stack; " id="oneliner_array_with_keys_tostring_attributes"

Now if you woud like to have comma separated instead of space separated string, just change the last replace into find "," with ','

the output would become

class="hi__stack--overflow",style="overflow: stack; ",id="oneliner_array_with_keys_tostring_attributes

Be aware, that this might be safe for html attributes (considering the values should never have a doubleqoute), but I would definitly not use it where the values can have the same combinations as the replaces have.

This is my first post, so, if you have any feedback. Feel free to let me know, also, if I by accident, did not abide by any standards, then let me know and i wil change it asap :)

Also if the question is outdated and the solution not requested anymore, I just found myself in the need of printing an array for debugging purposes (throwing an exception and showing the array that caused the problem).

For this reason, I anyway propose my simple solution (one line, like originally asked):

$array = ['a very' => ['complex' => 'array']];
$imploded = var_export($array, true);

This will return the exported var instead of directly printing it on the screen and the var $imploded will contain the full export.