want to count and separate each key in the array to a variable to assign them functions

Question

I am doing a key value pair with a for each loop to get post data, now i would like to catch each element in the rock array below separately so i can assign different functions to them

<input type = "text" name = "rock[bonjovi manson mettalica]">
foreach ($_POST as $key => $value) {
foreach($value as $k => $v){
echo '<p>'.$k.'</p>'; // this echo's all elements in the array, i would like to get each element in the array so i could assign them the below functions
if ($k === "bonjovi"){
//do something
}
if ($k === "manson"){
//do something
}
if ($k === "mettalica"){
//do something
}
}
}

Answer 1

Adding brackets to the Name of an input like rock[] denotes an array for php when the form is submitted; adding text inside the brackets assigns a name to the element of the array:

<input type="text" name="rock[ a b c ]">

$_POST

array(1) {
  ["rock"]=>
  array(1) {
    [" a b c "]=>
    string(5) "d e f"
  }
}

Maybe instead you want checkboxes? Or other examples here https://secure.php.net/manual/en/faq.html.php#faq.html.select-multiple

<input type="checkbox" name="rock[a]" value="A"> A 
<input type="checkbox" name="rock[b]" value ="B"> B
<input type="checkbox" name="rock[c]" value="C"> C
<input type="submit">

$_POST

array(1) {
  ["rock"]=>
  array(2) {
    ["a"]=>
    string(1) "A"
    ["c"]=>
    string(1) "C"
  }
}

Answer 2

foreach ($_POST as $key => $value)
$_POST contains all POST data, in your case you might want to try
foreach ($_POST["rock"] as $key => $value) to only access the content within 'rock'