{"id":1649,"date":"2021-05-14T07:07:27","date_gmt":"2021-05-14T07:07:27","guid":{"rendered":"https:\/\/phptutorial.net\/?page_id=1649"},"modified":"2025-04-07T14:24:51","modified_gmt":"2025-04-07T14:24:51","slug":"php-multiple-checkboxes","status":"publish","type":"page","link":"https:\/\/www.phptutorial.net\/php-tutorial\/php-multiple-checkboxes\/","title":{"rendered":"PHP Multiple Checkboxes"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn how to handle a form with multiple checkboxes in PHP.<\/p>\n\n\n\n

How to handle multiple checkboxes on a form #<\/a><\/h2>\n\n\n\n

A form may contain multiple checkboxes<\/a> with the same name. When you submit the form, you’ll receive multiple values on the server under one name. <\/p>\n\n\n\n

To get all the values from the checked checkboxes, you need to add the square brackets ([]<\/code>) after the name of the checkboxes. <\/p>\n\n\n\n

When PHP sees the square brackets ([]<\/code>) in the field name, it’ll create an associative array<\/a> of values where the key is the checkbox’s name and the values are the selected values.<\/p>\n\n\n\n

The following example shows a form that consists of three checkboxes with the same name (colors[]<\/code>) with different values \"red\"<\/code>, \"green\"<\/code>, and \"blue\"<\/code>.<\/p>\n\n\n

<form action=\"index.php\"<\/span> method=\"post\"<\/span>>\n\t<input type=\"checkbox\"<\/span> name=\"colors[]\"<\/span> value=\"red\"<\/span> id=\"color_red\"<\/span> \/>\n\t<label for<\/span>=\"color_red\"<\/span>>Red<\/label>\n\n\t<input type=\"checkbox\"<\/span> name=\"colors[]\"<\/span> value=\"green\"<\/span> id=\"color_green\"<\/span> \/>\n\t<label for<\/span>=\"color_red\"<\/span>>Green<\/label>\n\n\t<input type=\"checkbox\"<\/span> name=\"colors[]\"<\/span> value=\"blue\"<\/span> id=\"color_blue\"<\/span> \/>\n\t<label for<\/span>=\"color_red\"<\/span>>Blue<\/label>\n        <input type=\"submit\"<\/span> value=\"Submit\"<\/span>>\n<\/form><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
When you check three checkboxes and submit the form, the $_POST['colors']<\/code> will contain an array of three selected values:<\/p>\n\n\n
array(3) \n{ \n    [0]=> string(3) \"red\" \n    [1]=> string(5) \"green\" \n    [2]=> string(4) \"blue\" \n}<\/code><\/span>Code language:<\/span> plaintext<\/span> (<\/span>plaintext<\/span>)<\/span><\/small><\/pre>\n\n\n
If you don’t check any checkboxes and submit the form, the $_POST<\/code> array won’t have the colors<\/code> key. And you can use the isset()<\/code> function to check if the $_POST['colors']<\/code> is set:<\/p>\n\n\n
isset<\/span>($_POST['colors'<\/span>])<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
filter_has_var(INPUT_POST, 'colors'<\/span>)<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
PHP multiple checkboxes example #<\/a><\/h2>\n\n\n\n
We’ll create a simple app that allows users to order pizza toppings<\/a>.<\/p>\n\n\n
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\"PHP<\/figure>\n<\/div>\n\n\n
First, create the following file and directory structure:<\/p>\n\n\n
.\n\u251c\u2500\u2500 css\n\u2502   \u2514\u2500\u2500 style.css\n\u251c\u2500\u2500 img\n\u2502   \u2514\u2500\u2500 pizza.svg\n\u251c\u2500\u2500 inc\n\u2502   \u251c\u2500\u2500 .htaccess\n\u2502   \u251c\u2500\u2500 footer.php\n\u2502   \u251c\u2500\u2500 functions.php\n\u2502   \u251c\u2500\u2500 get.php\n\u2502   \u251c\u2500\u2500 header.php\n\u2502   \u2514\u2500\u2500 post.php\n\u2514\u2500\u2500 index.php<\/code><\/span>Code language:<\/span> plaintext<\/span> (<\/span>plaintext<\/span>)<\/span><\/small><\/pre>\n\n\n
File<\/th>Directory<\/th>Description<\/th><\/tr><\/thead>
index.php<\/td>.<\/td>Contain the main logic that loads get.php or post.php depending on the HTTP request method<\/td><\/tr>
get.php<\/td>inc<\/td>Contain the code for showing a form with a checkbox when the HTTP request is GET.<\/td><\/tr>
post.php<\/td>inc<\/td>Contain the code for handling POST request<\/td><\/tr>
header.php<\/td>inc<\/td>Contain the code for the header<\/td><\/tr>
footer.php<\/td>inc<\/td>Contain the code for the footer<\/td><\/tr>
functions.php<\/td>inc<\/td>Contain the common functions<\/td><\/tr>
.htaccess<\/td>inc<\/td>Prevent direct access to the files in the inc directory<\/td><\/tr>
style.css<\/td>css<\/td>Contain the CSS code<\/td><\/tr>
pizza.svg<\/td>img<\/td>The pizza image that shows on the form<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
Second, add the following code to the header.php<\/code>:<\/p>\n\n\n
<!DOCTYPE html<\/span>><\/span>\n<html<\/span> lang<\/span>=\"en\"<\/span>><\/span>\n\n<head<\/span>><\/span>\n    <meta<\/span> charset<\/span>=\"UTF-8\"<\/span> \/><\/span>\n    <meta<\/span> name<\/span>=\"viewport\"<\/span> content<\/span>=\"width=device-width, initial-scale=1.0\"<\/span> \/><\/span>\n    <link<\/span> rel<\/span>=\"preconnect\"<\/span> href<\/span>=\"https:\/\/fonts.gstatic.com\"<\/span>><\/span>\n    <link<\/span> href<\/span>=\"https:\/\/fonts.googleapis.com\/css2?family=Nanum+Gothic+Coding:wght@400;700&display=swap\"<\/span> rel<\/span>=\"stylesheet\"<\/span>><\/span>\n    <link<\/span> rel<\/span>=\"stylesheet\"<\/span> href<\/span>=\"css\/style.css\"<\/span>><\/span>\n    <title<\/span>><\/span>PHP Multiple Checkboxes - Pizza Toppings<\/title<\/span>><\/span>\n<\/head<\/span>><\/span>\n\n<body<\/span> class<\/span>=\"center\"<\/span>><\/span>\n    <main<\/span>><\/span>\n        <p<\/span>><\/span><img<\/span> src<\/span>=\"img\/pizza.svg\"<\/span> height<\/span>=\"72\"<\/span> width<\/span>=\"72\"<\/span> title<\/span>=\"Pizza Toppings\"<\/span>><\/span><\/p<\/span>><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
Note that the page uses the Nanum Gothic Coding font. The header.php<\/code> links to the style.css file. At the beginning of the body, it shows the pizza.svg<\/code> image.<\/p>\n\n\n\n
Third, add the following code to the footer.php<\/code>:<\/p>\n\n\n
<\/main<\/span>><\/span>\n<\/body<\/span>><\/span>\n<\/html<\/span>><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
The footer.php<\/code> file contains the closing tags corresponding to the opening tags in the header.php<\/code> file.<\/p>\n\n\n\n
Fourth, define a function checked in the functions.php<\/code> file:<\/p>\n\n\n
<?php<\/span>\n\nfunction<\/span> checked<\/span>($needle, $haystack)<\/span>\n<\/span>{\n\tif<\/span> ($haystack) {\n\t\treturn<\/span> in_array($needle, $haystack) ? 'checked'<\/span> : ''<\/span>;\n\t}\n\n\treturn<\/span> ''<\/span>;\n}<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The checked()<\/code> function returns the string 'checked'<\/code> if the $need<\/code> exists in the array $haystack<\/code> or an empty string otherwise.<\/p>\n\n\n\n
We’ll use this checked()<\/code> function to refill the selected checkboxes on the form.<\/p>\n\n\n\n
Fifth, add the following code to the index.php:<\/p>\n\n\n
<?php<\/span>\n\nsession_start();\n\nrequire<\/span> 'inc\/header.php'<\/span>;\n\nrequire<\/span> 'inc\/functions.php'<\/span>;\n\n$pizza_toppings = [\n\t'pepperoni'<\/span> => 0.5<\/span>,\n\t'mushrooms'<\/span> => 1<\/span>,\n\t'onions'<\/span> => 1.5<\/span>,\n\t'sausage'<\/span> => 2.5<\/span>,\n\t'bacon'<\/span> => 1.0<\/span>,\n];\n\n$request_method = $_SERVER['REQUEST_METHOD'<\/span>];\n\nif<\/span> ($request_method === 'GET'<\/span>) {\n\trequire<\/span> 'inc\/get.php'<\/span>;\n} elseif<\/span> ($request_method === 'POST'<\/span>) {\n\trequire<\/span> 'inc\/post.php'<\/span>;\n}\n\nrequire<\/span> 'inc\/footer.php'<\/span>;<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
How the index.php works.<\/p>\n\n\n\n
The index.php calls the session_start()<\/code> function to start (or resume) a session. It loads the code from the header.php, functions.php, and footer.php.<\/p>\n\n\n\n
The $pizza_toppings<\/code> array stores the pizza toppings and prices. In a real application, you may get it from a database or an API.<\/p>\n\n\n\n
If the HTTP method is GET, the index.php loads the form from the get.php file. In case the HTTP method is POST, it loads the code from the post.php file.<\/p>\n\n\n\n
Sixth, create a form in the get.php<\/code> file:<\/p>\n\n\n
<form action=\"<?php echo htmlspecialchars($_SERVER['PHP_SELF']) ?>\"<\/span> method=\"post\"<\/span>>\n\n    <h1>Please select your pizza toppings:<\/h1>\n    <ul>\n        <?php<\/span> foreach<\/span> ($pizza_toppings as<\/span> $topping => $price) : ?><\/span>\n            <li>\n                <div>\n                    <input type=\"checkbox\"<\/span> name=\"pizza_toppings[]\"<\/span> value=\"<?php echo $topping ?>\"<\/span> id=\"pizza_topping_<?php echo $topping ?>\"<\/span> <?php<\/span> echo<\/span> checked($topping, $_SESSION['selected_toppings'<\/span>] ?? []) ?><\/span> \/>\n                    <label for<\/span>=\"pizza_topping_<?php echo $topping ?>\"<\/span>><?php<\/span> echo<\/span> ucfirst($topping) ?><\/span><\/label>\n                <\/div>\n                <span><?php<\/span> echo<\/span> '$'<\/span> . $price ?><\/span><\/span>\n            <\/li>\n        <?php<\/span> endforeach<\/span> ?><\/span>\n    <\/ul>\n\n    <button type=\"submit\"<\/span>>Order Now<\/button>\n<\/form><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The get.php file uses the $pizza_toppings<\/code> array to dynamically generate checkboxes. The checked()<\/code> function checks the checkbox if the value exists in the $_SESSION['selected_toppings']<\/code> variable. <\/p>\n\n\n\n
When the page loads for the first time, the $_SESSION['selected_toppings']<\/code> is always empty. Later, we’ll add the selected values to it in the post.php<\/code>.<\/p>\n\n\n\n
Finally, place the code to handle form submission in the post.php<\/code> file:<\/p>\n\n\n
<?php<\/span>\n\n\nif<\/span> (filter_has_var(INPUT_POST, 'pizza_toppings'<\/span>)) {\n    \/\/ get the pizza toppings from the form<\/span>\n    $selected_toppings = filter_input(INPUT_POST, 'pizza_toppings'<\/span>,  FILTER_DEFAULT, FILTER_REQUIRE_ARRAY) ?? [];\n\n    \/\/ select the topping names<\/span>\n    $toppings = array_keys($pizza_toppings);\n\n    $_SESSION['selected_toppings'<\/span>] = []; \/\/ for storing selected toppings<\/span>\n    $total = 0<\/span>; \/\/ for storing total<\/span>\n\n    \/\/ check data against the original values<\/span>\n    if<\/span> ($selected_toppings) {\n        foreach<\/span> ($selected_toppings as<\/span> $topping) {\n            if<\/span> (in_array($topping, $toppings)) {\n                $_SESSION['selected_toppings'<\/span>][] = $topping;\n                $total += $pizza_toppings[$topping];\n            }\n        }\n    } \n    \n}\n?><\/span>\n\n\n<?php<\/span> if<\/span> ($_SESSION['selected_toppings'<\/span>]) : ?><\/span>\n    <h1>Order Summary<\/h1>\n    <ul>\n        <?php<\/span> foreach<\/span> ($_SESSION['selected_toppings'<\/span>] as<\/span> $topping) : ?><\/span>\n            <li>\n                <span><?php<\/span> echo<\/span> ucfirst($topping) ?><\/span><\/span>\n                <span><?php<\/span> echo<\/span> '$'<\/span> . $pizza_toppings[$topping] ?><\/span><\/span>\n            <\/li>\n        <?php<\/span> endforeach<\/span> ?><\/span>\n\n        <li class<\/span>=\"total<\/span>\"><span<\/span>>Total<\/span><\/span<\/span>><span<\/span>><?php<\/span> echo<\/span> '$' . $total<\/span> ?><\/span<\/span>><\/li<\/span>>\n    <\/ul<\/span>>\n<?php<\/span> else<\/span> : ?>\n    <p<\/span>>You<\/span> didn<\/span>'t<\/span> select<\/span> any<\/span> pizza<\/span> toppings<\/span>.<\/p<\/span>>\n<?php<\/span> endif<\/span> ?>\n\n<menu<\/span>>\n    <a<\/span> class<\/span>=\"btn<\/span>\" href<\/span>=\"<?= htmlentities<\/span>($_SERVER<\/span>['PHP_SELF<\/span>']) ?>\" title<\/span>=\"Back<\/span> to<\/span> the<\/span> form<\/span>\">Change<\/span> Toppings<\/span><\/a<\/span>>\n<\/menu<\/span>><\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The post.php<\/code> file get the form input using the filter_input()<\/a><\/code> function:<\/p>\n\n\n
 $selected_toppings = filter_input(INPUT_POST, 'pizza_toppings'<\/span>,  FILTER_DEFAULT, FILTER_REQUIRE_ARRAY) ?? [];<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
It checks selected pizza toppings against the original values in the $pizza_toppings<\/code> array and adds the selected values to the $_SESSION['selected_toppings']<\/code> variable. Also, it calculates the total price based on the selected pizza toppings.<\/p>\n\n\n
$toppings = array_keys($pizza_toppings);\n\n$_SESSION['selected_toppings'<\/span>] = []; \/\/ for storing selected toppings<\/span>\n$total = 0<\/span>; \/\/ for storing total<\/span>\n\n\/\/ check data against the original values<\/span>\nif<\/span> ($selected_toppings) {\n\tforeach<\/span> ($selected_toppings as<\/span> $topping) {\n\t\tif<\/span> (in_array($topping, $toppings)) {\n\t\t\t$_SESSION['selected_toppings'<\/span>][] = $topping;\n\t\t\t$total += $pizza_toppings[$topping];\n\t\t}\n\t}\n}<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The markup part shows the order summary if one or more pizza toppings are selected.<\/p>\n\n\n\n
Summary #<\/a><\/h2>\n\n\n\n
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  • Add square brackets ([]<\/code>) at the end of the checkbox name when a form has multiple checkboxes with the same name. <\/li>\n\n\n\n
  • PHP creates an associative array to stored values of the selected checkboxes if checkboxes have the same name that ends with []<\/code>.<\/li>\n<\/ul>\n
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    Did you find this tutorial useful?<\/div>\n\t\t
    \n\t\t\t\n\t\t\t\t\n\t\t\t\t\t<\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t Yes <\/span>\n\t\t\t<\/button>\n\n\t\t\t\n\t\t\t\t\n\t\t\t\t\t<\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t No <\/span>\n\t\t\t<\/button>\n\t\t<\/div>\n\t<\/header>\n\n\t
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    <\/div>\n\t\t\t\n\t\t\t
Alternatively, you can use the filter_has_var()<\/a><\/code> function:<\/p>\n\n\n