If you don't know which checkboxes your page has (ex: if you are creating them dynamically) you can simply put a hidden field with the same name and 0 value right above the checkbox.
<input type="hidden" name="foo" value="0" />
<input type="checkbox" name="foo" value="1">
This way you will get 1 or 0 based on whether the checkbox is selected or not.
I love short hands so:
$isChecked = isset($_POST['myCheckbox']) ? "yes" : "no";
Try this
index.html
<form action="form.php" method="post">
Do you like stackoverflow?
<input type="checkbox" name="like" value="Yes" />
<input type="submit" name="formSubmit" value="Submit" />
</form>
form.php
<html>
<head>
</head>
<body>
<?php
if(isset($_POST['like']))
{
echo "<h1>You like Stackoverflow.<h1>";
}
else
{
echo "<h1>You don't like Stackoverflow.</h1>";
}
?>
</body>
</html>
Or this
<?php
if(isset($_POST['like'])) &&
$_POST['like'] == 'Yes')
{
echo "You like Stackoverflow.";
}
else
{
echo "You don't like Stackoverflow.";
}
?>
you can check that by either isset() or empty() (its check explicit isset) weather check box is checked or not
for example
<input type='checkbox' name='Mary' value='2' id='checkbox' />
here you can check by
if (isset($_POST['Mary'])) {
echo "checked!";
}
or
if (!empty($_POST['Mary'])) {
echo "checked!";
}
the above will check only one if you want to do for many than you can make an array instead writing separate for all checkbox try like
<input type="checkbox" name="formDoor[]" value="A" />Acorn Building<br />
<input type="checkbox" name="formDoor[]" value="B" />Brown Hall<br />
<input type="checkbox" name="formDoor[]" value="C" />Carnegie Complex<br />
php
$aDoor = $_POST['formDoor'];
if(empty($aDoor))
{
echo("You didn't select any buildings.");
}
else
{
$N = count($aDoor);
echo("You selected $N door(s): ");
for($i=0; $i < $N; $i++)
{
echo htmlspecialchars($aDoor[$i] ). " ";
}
}
Source: Stackoverflow.com