How can I loop through an associative array and get the key?

If you use array_keys(), PHP will give you an array filled with just the keys:

$keys = array_keys($arr);
foreach ($keys as $key) {
    echo $key;
}

Alternatively, you can do this:

foreach ($arr as $key => $value) {
    echo $key;
}

It can be done with a regular for loop. Sometimes I find it more readable and prefer for over foreach.
So here it is:

$array = array('key1' => 'value1', 'key2' => 'value2');

$keys = array_keys($array);

for($i=0; $i < count($keys); ++$i) {
    echo $keys[$i] . ' ' . $array[$keys[$i]] . "\n";
}

/*
  prints:
  key1 value1
  key2 value2
*/

foreach($array as $k => $v)

Where $k is the key and $v is the value

Or if you just need the keys use array_keys()

I use the following loop to get the key and value from an associative array

foreach ($array as $key => $value)
{
  echo "<p>$key = $value</p>";
}

The following will allow you to get at both the key and value at the same time.

foreach ($arr as $key => $value)
{
  echo($key);
}

While arguably being less clear, this method is faster by roughly a factor of roughly 3.5 (at least on the box I used to test):

$foo = array(
    1 => "Value1",
    2 => "Value2",
    10 => "Value10"
);
while($bar = each($foo)){
    echo $bar[0] . " => " . $bar[1];
}

I would imagine that this is due to the fact the foreach copies the entire array before iterating over it.

 foreach($arr as $key=>$value){
    echo($key);    // key
 }

Use $key => $val to get the keys:

<?php

$arr = array(
    1 => "Value1",
    2 => "Value2",
    10 => "Value10",
);

foreach ($arr as $key => $val) {
   print "$key\n";
}

?>

<?php
$names = array("firstname"=>"maurice",
               "lastname"=>"muteti", 
               "contact"=>"7844433339");

foreach ($names as $name => $value) {
    echo $name." ".$value."</br>";
}

print_r($names);
?>

Oh I found it in the PHP manual.

foreach ($array as $key => $value){
    statement
}

The current element's key will be assigned to the variable $key on each loop.