How do I see which checkbox is checked?

StackOverflow https://stackoverflow.com/questions/2268887

Question

How do I check in PHP whether a checkbox is checked or not?

Was it helpful?

Solution

If the checkbox is checked, then the checkbox's value will be passed. Otherwise, the field is not passed in the HTTP post.

if (isset($_POST['mycheckbox'])) {
    echo "checked!";
}

OTHER TIPS

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] ). " ";
    }
  }

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.";
    }   
?>

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";
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