Implode with array with keys in PHP - php

Question

I need to write an array to a .csv file in PHP.
Example array:
$array = array(
"name" => "John",
"surname" => "Doe",
"email" => "nowhere#nowhere.com"
);
By using implode(",", $array), I get a result like this:
John,Doe,nowhere#nowhere.com
However, I need to also write the key of each element to the file.
The desired output is this:
name:John,surname:Doe,email:nowhere#nowhere.com
How would I achieve this?

Answer 1

Try this code:
$out = $sep = '';
foreach( $array as $key => $value ) {
$out .= $sep . $key . ':' . $value;
$sep = ',';
}

Answer 2

$csv = "";
foreach($array as $key => $data)
{
// be sure to add " in your csv
$csv .= '"'.$key.':'.$data.'",';
}
// and add a new line at the end
$csv .= "\n";
echo $csv;

Answer 3

The answers above outputs a trailing comma at the end. To correct this, I use the following function:
$array = array(
"name" => "John",
"surname" => "Doe",
"email" => "nowhere#nowhere.com"
);
function implodeKV($glueKV, $gluePair, $KVarray){
$t = array();
foreach($KVarray as $key=>$val) {
$t[] = $key . $glueKV . $val;
}
return implode($gluePair, $t);
}
echo implodeKV( ':' , ',' , $array);
// outputs name:John,surname:Doe,email:nowhere#nowhere.com
http://phpassist.com/2dde2#2

Answer 4

If you're using PHP 5.3+, then an anonymous function can make your code a lot cleaner, though a simple for loop has the best performance. (Using array_walk comes close though!)
I ran some tests with a few different approaches (using PHP 5.4.33):
function makeArray(&$a) {
$a = array();
for($i = 0; $i < 100000; $i++) {
$a[rand()] = rand();
}
return $a;
}
makeArray($array);
$before = microtime(true);
$result = implode(
",",
array_map(
function($k, $v) {
return "$k:$v";
},
array_keys($array),
$array
)
);
$after = microtime(true);
$dur = $after - $before;
echo "Array Map w/ anonymous function: {$dur}s<br>";
makeArray($array);
$before = microtime(true);
function kv_func($k, $v) {
return "$k:$v";
}
$result = implode(
",",
array_map(
"kv_func",
array_keys($array),
$array
)
);
$after = microtime(true);
$dur = $after - $before;
echo "Array Map w/ function: {$dur}s<br>";
makeArray($array);
$before = microtime(true);
array_walk(
$array,
function(&$v, $k) {
$v = "$k:$v";
}
);
$result = implode(
",",
$array
);
$after = microtime(true);
$dur = $after - $before;
echo "Array Walk w/ anonymous function: {$dur}s<br>";
makeArray($array);
$before = microtime(true);
$ff = true;
$sep = ",";
$out = "";
foreach($array as $key => $val) {
if($ff) $ff = false;
else $out .= $sep;
$out .= "$key:$val";
}
$after = microtime(true);
$dur = $after - $before;
echo "Foreach loop w/ loop flag: {$dur}s<br>";
makeArray($array);
$before = microtime(true);
$out = "";
foreach($array as $key => $val) {
$out .= "$key:$val,";
}
$out = substr($out, 0, -1);
$after = microtime(true);
$dur = $after - $before;
echo "Foreach loop + substr: {$dur}s<br>";
Results:
Array Map w/ anonymous function: 0.13117909431458s
Array Map w/ function: 0.13743591308594s // slower than anonymous
Array Walk w/ anonymous function: 0.065797805786133s // close second
Foreach loop w/ loop flag: 0.042901992797852s // fastest
Foreach loop + substr: 0.043946027755737s // comparable to the above
And just for kicks, I tried the for loop without correcting for the trailing comma. It didn't really have any impact:
Foreach loop w/ trailing comma: 0.044748067855835s

Answer 5

<?php
$array = array(
"name" => "John",
"surname" => "Doe",
"email" => "nowhere#nowhere.com"
);
foreach( $array as $key=>$data ) {
$output .= $comma . $key . ':' . $data;
$comma = ',';
}
echo $output;
?>