[php] PHP Multiple Checkbox Array

I've looked around for a few examples here but a lot of them are either too advanced for my grasp of PHP or their examples are too specific to their own projects. I am currently struggling with a very basic part of a PHP form.

I am trying to create a form with a few checkboxes, each assigned a different value, I want these to be sent to a variable (array?) that I can echo/use later, in my case I will be sending the checked values in an email.

So far, I have tried a few variations, but the closest I have come to it is this...

<form method='post' id='userform' action='thisform.php'>
<tr>
    <td>Trouble Type</td>
    <td>
    <input type='checkbox' name='checkboxvar' value='Option One'>1<br>
    <input type='checkbox' name='checkboxvar' value='Option Two'>2<br>
    <input type='checkbox' name='checkboxvar' value='Option Three'>3
    </td>
</tr>
</table>
<input type='submit' class='buttons'>
</form>

<?php
$checkboxvar[] = $_REQUEST['checkboxvar'];
?>

Where I'd echo $checkboxvar[] into my email. Am I going about this completely wrong? The other idea I had was to use a lot of if statements.

add [] in the name of the attributes in the input tag

 <form action="" name="frm" method="post">
<input type="checkbox" name="hobby[]" value="coding">  coding &nbsp
<input type="checkbox" name="hobby[]" value="database">  database &nbsp
<input type="checkbox" name="hobby[]" value="software engineer">  soft Engineering <br>
<input type="submit" name="submit" value="submit"> 
</form>

for PHP Code :

<?php
 if(isset($_POST['submit']){
   $hobby = $_POST['hobby'];

   foreach ($hobby as $hobys=>$value) {
             echo "Hobby : ".$value."<br />";
        }
}
?>

if (isset($_POST['submit'])) {

for($i = 0; $i<= 3; $i++){

    if(isset($_POST['books'][$i]))

        $book .= ' '.$_POST['books'][$i];
}

Also remember you can include custom indices to the array sent to the server like this

<form method='post' id='userform' action='thisform.php'>
<tr>
    <td>Trouble Type</td>
    <td>
    <input type='checkbox' name='checkboxvar[4]' value='Option One'>4<br>
    <input type='checkbox' name='checkboxvar[6]' value='Option Two'>6<br>
    <input type='checkbox' name='checkboxvar[9]' value='Option Three'>9
    </td>
</tr>
<input type='submit' class='buttons'>
</form>

This is particularly useful when you want to use the id of individual objects in a server array accounts (for instance) to send data back to the server and recognize same at server

<form method='post' id='userform' action='thisform.php'>
<tr>
    <td>Trouble Type</td>
    <td>
    <?php foreach($accounts as $account) { ?>
        <input type='checkbox' name='accounts[<?php echo $account->id ?>]' value='<?php echo $account->name ?>'>
        <?php echo $account->name ?>
        <br>
    <?php } ?>
    </td>
</tr>
<input type='submit' class='buttons'>
</form>

<?php 
if (isset($_POST['accounts'])) 
{
    print_r($_POST['accounts']); 
}
?>

Try this, by for Loop

<form method="post">
<?php
for ($i=1; $i <5 ; $i++) 
{ 
    echo'<input type="checkbox" value="'.$i.'" name="checkbox[]"/>';
} 
?>
<input type="submit" name="submit" class="form-control" value="Submit">  
</form>

<?php 
if(isset($_POST['submit']))
{
    $check=implode(", ", $_POST['checkbox']);
    print_r($check);
}     
?>

You need to use the square brackets notation to have values sent as an array:

<form method='post' id='userform' action='thisform.php'>
<tr>
    <td>Trouble Type</td>
    <td>
    <input type='checkbox' name='checkboxvar[]' value='Option One'>1<br>
    <input type='checkbox' name='checkboxvar[]' value='Option Two'>2<br>
    <input type='checkbox' name='checkboxvar[]' value='Option Three'>3
    </td>
</tr>
</table>
<input type='submit' class='buttons'>
</form>

Please note though, that only the values of only checked checkboxes will be sent.