Can I assign values to a checkbox for checked and unchecked states?

问题

I have a single checkbox in a form which I want to assign values to for both checked and unchecked states. The values are saved in a MySQL database. This is my php to retrieve the values.

<?php
// Value = 10.00
// This should be the checked value (initial state)
function getDel1()
{
global $con;
$get_del1 = "select * from delivery";
$run_del1 = mysqli_query($con, $get_del1);
while($row_del1=mysqli_fetch_array($run_del1)){
$leeds = $row_del1['delivery_leeds'];
echo "$leeds";
}
}
?>

<?php
// Value = 20.00
// This should be the unchecked value (user interaction)
function getDel2()
{
global $con;
$get_del2 = "select * from delivery";
$run_del2 = mysqli_query($con, $get_del2);
while($row_del2=mysqli_fetch_array($run_del2)){
$leeds = $row_del2['delivery_other'];
echo "$other";
}
}
?>

I can display the values independently by calling either function in a div which is adjacent to the form checkbox but I don't know how to assign those values to the form checkbox and then automatically update the div depending on the user interaction. Any suggestions?

回答1:

A ternary operator can take care of both assigned values and unassigned default values.

Example:

$checkbox = isset($_POST['checkbox']) ? $_POST['checkbox'] : "Default value if unchecked";

This is equivalent to doing: (which you can also use).

if (isset($_POST['checkbox'])){
    $checkbox=$_POST['checkbox'];

// do something, as in run a function

}
else{
    $checkbox="Default value if unchecked";

// do something else, as in run a different function

}

You can also remove the default text and do "" in the ternary to leave it empty.

Reference:

http://php.net/manual/en/language.operators.comparison.php

Footnotes:

Make sure the checkbox holds the name attribute.

I.e. name="checkbox" as an example.

and your form has a POST method. Use the appropriate method accordingly.

So in your case and as seen in comments from code you left there, change checkbox in the arrays to deliver.

Your checkbox value can also use the following, as a ternary example:

<input type="checkbox" name="deliver" value="<?php echo isset($_POST['deliver']) ? $_POST['deliver'] : "Default value if unchecked"; ?>" />

来源：https://stackoverflow.com/questions/33281558/can-i-assign-values-to-a-checkbox-for-checked-and-unchecked-states

标签

php

checkbox