在PHP中添加新的数组元素

I have an array variable $data as below:

$data = array (
'deptIDid' =>array(
    'userid' =>array(
        '12:00' => array(
            'bookname'= 'Chemistry',
            'return'= 'false'
            )

        '12:01' => array(),
        '12:02' => array(),
        '12:03' => array(),
        '12:04' => array(),
        '12:05' => array(),
        '12:06' => array(),
        '12:07' => array(
            'bookname'= ''
            'return'= 'true'
        ),
        '12:08' => array(
            'bookname'= 'Math',
            'return'= 'false'
        ),
        '12:09' => array(),
        '12:10' => array(),
        '12:11' => array(),
        '12:12' => array(),
    ),
  )
)

The logic is the user borrowed a book in the department library. Inside the time array there is two elements userid and return. What I need to do is when the time array does not have a value. It should add a value similar from the early time until the return value become true. The output should be:

 $data = array (
'deptIDid' =>array(
    'userid' =>array(
        '12:00' => array(
            'bookname'=> 'Chemistry',
            'return'=> 'false'
            )

        '12:01' => array(
            'bookname'=> 'Chemistry',
            'return'=> 'false'
            ),
        '12:02' => array(
            'bookname'=> 'Chemistry',
            'return'=> 'false'),
        '12:03' => array(
            'bookname'=> 'Chemistry',
            'return'=> 'false'),
        '12:04' => array(
            'bookname'=> 'Chemistry',
            'return'=> 'false'),
        '12:05' => array(
            'bookname'=> 'Chemistry',
            'return'=> 'false'),
        '12:06' => array(
            'bookname'=> 'Chemistry',
            'return'=> 'false'),
        '12:07' => array(
            'bookname'=> 'Chemistry'
            'return'=> 'true'
        ),
        '12:08' => array(
            'bookname'=> 'Math',
            'return'=> 'false'
        ),
        '12:09' => array(
            'bookname'=> 'Math',
            'return'=> 'false'
        ),
        '12:10' => array(
            'bookname'=> 'Math',
            'return'=> 'false'
        ),
        '12:11' => array(
            'bookname'=> 'Math',
            'return'=> 'false'
        ),
        '12:12' => array(
            'bookname'=> 'Math',
            'return'=> 'false'
        ),
    ),
   )
 )

Try this:

Check if array empty then add array as described below:

$val = '';
foreach($data['deptIDid']['userid'] as $key=>$d) {
 if(trim($data['deptIDid']['userid'][$key]['bookname']) != '') {
    $val= $data['deptIDid']['userid'][$key]['bookname'];
 }
 if(empty($d) || $data['deptIDid']['userid'][$key]['bookname'] == '') {
    $data['deptIDid']['userid'][$key] = array('bookname'=> $val,'return'=> 'false');
 }
}
print '<pre>';print_r($data);
exit;

Output:

Array
(
    [deptIDid] => Array
        (
            [userid] => Array
                (
                    [12:00] => Array
                        (
                            [bookname] => Chemistry
                            [return] => false
                        )

                    [12:01] => Array
                        (
                            [bookname] => Chemistry
                            [return] => false
                        )

                    [12:02] => Array
                        (
                            [bookname] => Chemistry
                            [return] => false
                        )

                    [12:03] => Array
                        (
                            [bookname] => Chemistry
                            [return] => false
                        )

                    [12:04] => Array
                        (
                            [bookname] => Chemistry
                            [return] => false
                        )

                    [12:05] => Array
                        (
                            [bookname] => Chemistry
                            [return] => false
                        )

                    [12:06] => Array
                        (
                            [bookname] => Chemistry
                            [return] => false
                        )

                    [12:07] => Array
                        (
                            [bookname] => Chemistry
                            [return] => false
                        )

                    [12:08] => Array
                        (
                            [bookname] => Math
                            [return] => false
                        )

                    [12:09] => Array
                        (
                            [bookname] => Math
                            [return] => false
                        )

                    [12:10] => Array
                        (
                            [bookname] => Math
                            [return] => false
                        )

                    [12:11] => Array
                        (
                            [bookname] => Math
                            [return] => false
                        )

                    [12:12] => Array
                        (
                            [bookname] => Math
                            [return] => false
                        )

                )

        )

)

Adjusted Dhara's code a bit:

$prevData = [];
foreach($data['deptIDid']['userid'] as $key => $d) {
    if(empty($d)) {
        $data['deptIDid']['userid'][$key] = $prevData;
    } else {
        $prevData = $d;
    }
}

foreach($data['deptIDid']['userid'] as $key=>$val)
{   
    if(count($val)>0)
    {
        if($val['bookname']=="")
        {
            $val['bookname']=$tamp['bookname']; 
        }
        else if($val['return'] == "")
        {
                $val['return']=$tamp['return'];
        }
        $tamp = $val;   
        $tarray[$key] = $val;

    }
    else
    {
        $tarray[$key]=$tamp;
    }
}