php array implode - php

Question

I have this array:
array (size=5)
35 => string '3' (length=1)
24 => string '6' (length=1)
72 => string '1' (length=1)
16 => string '5' (length=1)
81 => string '2' (length=1)
I want to implode id to get:
$str = '35-3|24-6|72-1|16-5|81-2';
How to get it the easy way?
Thanks.

Answer 1

One possibility would be like this
function mapKeyVal($k, $v) {
return $k . '-' . $v;
}
echo implode('|', array_map('mapKeyVal',
array_keys($arry),
array_values($arry)
)
);

Answer 2

I haven't tested this, but it should be pretty straight forward ...
foreach($array as $key=>$item){
$new_arr[] = $key."-".$item;
}
$str = implode('|', $new_arr);

Answer 3

You cannot can do this using implode, see #havelock's answer below, however it would be easier to use a loop or another form of iteration.
$str = "";
foreach ($array as $key => $value) {
$str .= $key . "-" . $value . "|";
}
$str = substr(0, strlen($str)-1);

Answer 4

Solution
You can do it cleanly by joining strings, while using eg. custom associative mapping function, which looks like that:
function array_map_associative($callback, $array){
$result = array();
foreach ($array as $key => $value){
$result[] = call_user_func($callback, $key, $value);
}
return $result;
}
Full example and test
The full solution using it could look like that:
<?php
function array_map_associative($callback, $array){
$result = array();
foreach ($array as $key => $value){
$result[] = call_user_func($callback, $key, $value);
}
return $result;
}
function callback($key, $value){
return $key . '-' . $value;
}
$data = array(
35 => '3',
24 => '6',
72 => '1',
16 => '5',
81 => '2',
);
$result = implode('|', array_map_associative('callback', $data));
var_dump($result);
and the result is:
string(24) "35-3|24-6|72-1|16-5|81-2"
which matches what you expected.
The proof is here: http://ideone.com/HPsVO6