Get Name of a Post Variable

get name of a post variable

$_POST is populated as an associative array, so you can just do this:

foreach ($_POST as $name => $val)
{
     echo htmlspecialchars($name . ': ' . $val) . "\n";
}

Additionally, if you're just interested in the field names, you can use array_keys($_POST); to return an array of all the keys used in $_POST. You can use those keys to reference values in $_POST.

foreach (array_keys($_POST) as $field)
{
    echo $_POST[$field];
}

• foreach documentation
• array_keys documentation

$_POST variable name is variable, how to retrieve?

Add some quotes:

$user_input = $_POST["field$id"];

How can I extract the name of a $_POST variable, not its value_

As far as I understood, you are looking for array_keys($_POST).

Get all variables sent with POST?

The variable $_POST is automatically populated.

Try var_dump($_POST); to see the contents.

You can access individual values like this: echo $_POST["name"];

This, of course, assumes your form is using the typical form encoding (i.e. enctype=”multipart/form-data”

If your post data is in another format (e.g. JSON or XML, you can do something like this:

$post = file_get_contents('php://input');

and $post will contain the raw data.

Assuming you're using the standard $_POST variable, you can test if a checkbox is checked like this:

if(isset($_POST['myCheckbox']) && $_POST['myCheckbox'] == 'Yes')
{
     ...
}

If you have an array of checkboxes (e.g.

<form action="myscript.php" method="post">
  <input type="checkbox" name="myCheckbox[]" value="A" />val1<br />
  <input type="checkbox" name="myCheckbox[]" value="B" />val2<br />
  <input type="checkbox" name="myCheckbox[]" value="C" />val3<br />
  <input type="checkbox" name="myCheckbox[]" value="D" />val4<br />
  <input type="checkbox" name="myCheckbox[]" value="E" />val5
  <input type="submit" name="Submit" value="Submit" />
</form>

Using [ ] in the checkbox name indicates that the selected values will be accessed by PHP script as an array. In this case $_POST['myCheckbox'] won't return a single string but will return an array consisting of all the values of the checkboxes that were checked.

For instance, if I checked all the boxes, $_POST['myCheckbox'] would be an array consisting of: {A, B, C, D, E}. Here's an example of how to retrieve the array of values and display them:

  $myboxes = $_POST['myCheckbox'];
  if(empty($myboxes))
  {
    echo("You didn't select any boxes.");
  }
  else
  {
    $i = count($myboxes);
    echo("You selected $i box(es): <br>");
    for($j = 0; $j < $i; $j++)
    {
      echo $myboxes[$j] . "<br>";
    }
  }

how to deal with $_POST for a variable which is set as name of a input in a form - PHP

simply write

echo "<pre>";
print_r($_POST);
exit();

and you will get array which will help you.

Print $_POST variable name along with value

If you just want to print the entire $_POST array to verify your data is being sent correctly, use print_r:

print_r($_POST);

To recursively print the contents of an array:

printArray($_POST);

function printArray($array){
     foreach ($array as $key => $value){
        echo "$key => $value";
        if(is_array($value)){ //If $value is an array, print it as well!
            printArray($value);
        }  
    } 
}

Apply some padding to nested arrays:

printArray($_POST);

/*
 * $pad='' gives $pad a default value, meaning we don't have 
 * to pass printArray a value for it if we don't want to if we're
 * happy with the given default value (no padding)
 */
function printArray($array, $pad=''){
     foreach ($array as $key => $value){
        echo $pad . "$key => $value";
        if(is_array($value)){
            printArray($value, $pad.' ');
        }  
    } 
}

is_array returns true if the given variable is an array.

You can also use array_keys which will return all the string names.

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