How can I retrieve the keys of a PHP array?

Printing the Keys of an Array

In PHP, retrieving the keys of an array can be a straightforward process. Here's how to accomplish it:

Using array_keys()

The array_keys() function provides a convenient way to obtain the keys. Example:

<code class="php">$parameters = array(
  "day" => 1,
  "month" => 8,
  "year" => 2010
);

foreach (array_keys($parameters) as $key) {
  echo $key . "<br>";
}</code>

Using a Foreach Loop with Key-Value Separation

PHP's foreach loop can iterate through arrays while separating the key and value at each step:

<code class="php">foreach ($parameters as $key => $value) {
  echo $key . "<br>";
}</code>

Ensuring Proper Key Syntax

To avoid errors, ensure that your array keys are valid strings or integers. Example:

<code class="php">$parameters["day"] = 1; // Correct
$parameters[day] = 1;    // Also correct</code>

Example Usage

Using the example array provided in the question:

<code class="php">$parameters = array(
  "day" => 1,
  "month" => 8,
  "year" => 2010
);

foreach ($parameters as $key => $value) {
  echo $key . "<br>";
}</code>

Output:

day
month
year

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