我使用这个jQuery块，它将在提交时为每个未选中的复选框添加一个隐藏输入。它将保证您每次都为每个复选框提交一个值，而不会弄乱您的标记，并冒着忘记在稍后添加的复选框上执行此操作的风险。它也与您正在使用的任何后端堆栈(PHP、Ruby等)无关。

// Add an event listener on #form's submit action...
$("#form").submit(
    function() {

        // For each unchecked checkbox on the form...
        $(this).find($("input:checkbox:not(:checked)")).each(

            // Create a hidden field with the same name as the checkbox and a value of 0
            // You could just as easily use "off", "false", or whatever you want to get
            // when the checkbox is empty.
            function(index) {
                var input = $('<input />');
                input.attr('type', 'hidden');
                input.attr('name', $(this).attr("name")); // Same name as the checkbox
                input.attr('value', "0"); // or 'off', 'false', 'no', whatever

                // append it to the form the checkbox is in just as it's being submitted
                var form = $(this)[0].form;
                $(form).append(input);

            }   // end function inside each()
        );      // end each() argument list

        return true;    // Don't abort the form submit

    }   // end function inside submit()
);      // end submit() argument list

I see this question is old and has so many answers, but I'll give my penny anyway. My vote is for the javascript solution on the form's 'submit' event, as some has pointed out. No doubling the inputs (especially if you have long names and attributes with php code mixed with html), no server side bother (that would require to know all field names and to check them down one by one), just fetch all the unchecked items, assign them a 0 value (or whatever you need to indicate a 'not checked' status) and then change their attribute 'checked' to true

    $('form').submit(function(e){
    var b = $("input:checkbox:not(:checked)");
    $(b).each(function () {
        $(this).val(0); //Set whatever value you need for 'not checked'
        $(this).attr("checked", true);
    });
    return true;
});

这样你会得到一个像这样的$_POST数组:

Array
(
            [field1] => 1
            [field2] => 0
)

我更喜欢不需要javascript的解决方案(是的，我知道现在会有一些人把我归为勒德分子)，但如果你像我一样，你想要能够显示复选框的默认/初始设置，然后让它保持或更新基于提交的表单，试试这个(建立在上面的几个想法上):

设置确定初始复选框状态的变量，然后使用服务器检查确定每次提交表单后的显示。

下面的例子创建了一个数组的数组(用于WordPress;同样适用于其他地方)，然后使用服务器脚本确定复选框的状态，而不使用隐藏字段或javascript。

<?php

$options_array = array (
    array('list_companies_shortcode' , 'shortcode_list_companies' , 'List Companies Shortcode'),
    array('list_contacts_shortcode' , 'shortcode_list_contacts' , 'List Contacts Shortcode'),
    array('test_checkbox_1' , 'checked' , 'Label for Checkbox 1' , 'checkbox' , 'Some text to instruct the user on this checkbox use' ),
    array('test_checkbox_2' , '' , 'Label for Checkbox 2' , 'checkbox' , 'Some other text to instruct the user on this checkbox use' )
 ) ;


$name_value_array = array() ;
$name_label_array = array() ;
$field_type_array = array() ;
$field_descriptor_array = array() ;
foreach ( $options_array as $option_entry ) {
    $name_value_array[ $option_entry[0] ] = $option_entry[1] ;
    $name_label_array[ $option_entry[0] ] = $option_entry[2] ;
    if ( isset( $option_entry[3] ) ) {
        $field_type_array[ $option_entry[0] ] = $option_entry[3] ;
        $field_descriptor_array[ $option_entry[0] ] = $option_entry[4] ;
    } else {
        $field_type_array[ option_entry[0] ] = 'text' ;
        $field_descriptor_array[ $option_entry[0] ] = NULL ;
    } 
}

echo "<form action='' method='POST'>" ;
    foreach ( $name_value_array as $setting_name => $setting_value ) {
        if ( isset( $_POST[ 'submit' ] ) ) {
            if ( isset( $_POST[ $setting_name ] ) ) {
                $setting_value = $_POST[ $setting_name ] ;
            } else {
                $setting_value = '' ;
            }
        }   
        $setting_label = $option_name_label_array[ $setting_name ] ;
        $setting_field_type = $field_type_array[ $setting_name ] ;
        $setting_field_descriptor = $field_descriptor_array [ $setting_name ] ;
        echo "<label for=$setting_name >$setting_label</label>" ;
        switch ( $setting_field_type ) {
            case 'checkbox':
                echo "<input type='checkbox' id=" . $setting_name . " name=" . $setting_name . " value='checked' " . $setting_value . " >(" . $setting_field_descriptor . ")</input><br />" ;
                break ;
            default:
                echo "<input type='text' id=" . $setting_name . " name=" . $setting_name . " value=" . $setting_value . " ></input><br />" ;
        }
    }
    echo "<input type='submit' value='Submit' name='submit' >" ;
echo "</form>" ;

最简单的解决方案是一个“虚拟”复选框加上隐藏输入，如果你正在使用jquery:

 <input id="id" type="hidden" name="name" value="1/0">
 <input onchange="$('#id').val(this.checked?1:0)" type="checkbox" id="dummy-id" 
 name="dummy-name" value="1/0" checked="checked/blank">

将两个输入的值设置为当前的1/0值，如果为1，则checked=checked。输入字段(活动)现在将始终被发布为1或0。此外，复选框可以在提交前点击多次，仍然可以正常工作。

$('form').submit(function () {
    $(this).find('input[type="checkbox"]').each( function () {
        var checkbox = $(this);
        if( checkbox.is(':checked')) {
            checkbox.attr('value','1');
        } else {
            checkbox.after().append(checkbox.clone().attr({type:'hidden', value:0}));
            checkbox.prop('disabled', true);
        }
    })
});

当提交时复选框未选中时，将复选框的值更新为'NO'并设置checked = 'TRUE'

https://jsfiddle.net/pommyk/8d9jLrvo/26/

$(document).ready(function() 
{
  function save() 
  {
    if (document.getElementById('AgeVerification').checked == false) 
    {
      document.getElementById('AgeVerification').value = 'no';
      document.getElementById('AgeVerification').checked = true;     
    }
  }
  document.getElementById("submit").onclick = save;
})