在foreach循环php中跳过变量的第一个值

Question

I have the following function on my site which grabs all the values from $vid_pix , and echos each them or any associated variables in a foreach loop.

Which works fine, however I have a variable - $Pt that also gets echoed out as well.

Right now though what I am trying to do is - skip the first value in $Pt . Also set a static value for the last instance since everything is being moved up 1, leaving the last with no value.

I've tried array_splice and unset , but it's not skipping the first $Pt value.

So if I had -

[vp 1]->[5]
[vp 2]->[10]
[vp 3]->[15]
[vp 4]->[20]

I would need -

[vp 1]->[10]
[vp 2]->[15]
[vp 3]->[20]
[vp 4]->[x]

(x = I would have to assign a static value for the last variable.)

My function (stripped down for simplicity)

$vid_pix = get_post_meta($v_Id, 'vid_pix', false);

foreach ($vid_pix as $vP) {
    $Pt = get_post_meta($vP, 'photo_time', false);
    array_splice($Pt, 0, 1);
    //unset($Pt[0]);
    $Pt = get_post_meta($vP, 'photo_time', true);
    echo $Pt;

    if (last -> $Pt) { // something like this for the last value
        $Pt = '5';
    }
 }

To put things into better context, here's the full code for the specific function I'm trying to achieve this within --

/*
This is for looping through the uploaded pictures
and sorting them and creating a text file.
*/

$vid_pix = get_post_meta($v_Id, 'vid_pix', false);

$data = "ffconcat version 1.0";
$line = '';

        usort( $vid_pix, function( $a, $b ){
            $aPor = (int) get_post_meta( $a, 'photo_order', true );
            $bPor = (int) get_post_meta( $b, 'photo_order', true );

            if ( $aPor === $bPor ) {
                return 0;
            }

            return ( $aPor < $bPor ) ? -1 : 1;
        } );

        foreach ($vid_pix as $vP) {
$filename = basename( get_attached_file( $vP ));
$Pt = get_post_meta($vP, 'photo_time', true);
$Por = get_post_meta($vP, 'photo_order', true);

$static_value=25;
$array=$Pt;

reset($array);//reset the internal pointer
while(false!==($key=key($array))&&null!==key($array)){//check for current key validity
    $next=next($array);//get the next value and move the pointer
    $array[$key]=$next&&isset($array[$key])?$next:$static_value;//assign the next value to the current key  if valid or the static value if false 
}

var_dump($Por);
var_dump($array);

// try to determine the pic of the placeholder image

if ($vP === end($vid_pix))
        $last_img = $thepath.'/'.$filename;


if ($vstyle === 'Custom') { // if custom timing is chosen

$slide_dur = "\r\nduration ".$Pt;

$filename = basename( get_attached_file( $vP ));
$line .= "file '".$thepath."/".$filename."'".$slide_dur."\r\n";


} else { // if custom timing is NOT chosen

$filename = basename( get_attached_file( $vP ));
$line .= "file '".$thepath."/".$filename."'".$slide_dur."\r\n";

}

$total_items = count($vid_pix);

if ($total_items > 1) { // if total items is more than one

// LAST LINE OF CONCAT TEXT FILE
$lastline = "file '".$last_img."'\r\nduration 2\r\nfile '".$last_img."'";

$isitone = "";
$solopic = "";


// PUT TOGETHER ALL THE LINES FOR THE TEXT FILE
$txtc = $data."\r\n".$line.$lastline;

} else { // if total items is less than one

$isitone = "true";
$solopic = "-loop 1 -probesize 10M -i ".$thepath."/".$filename;

}
}

// SAVE THE TEXT FILE
file_put_contents($thepath.'/paths.txt', $txtc);

UPDATE

var_dump results -

string(1) "7"
string(1) "2"
string(1) "6"
string(1) "9"

The following link contains the original code which saves the $Pt variable -- here

Answer 1

Based on OP's comments , $Pt is an array of array. So we simply use array_shift to remove the first value (second level array). And, append an array of static value to the end:

$vid_pix = get_post_meta($v_Id, 'vid_pix', false);

foreach ($vid_pix as $vP) {
    $Pt = get_post_meta($vP, 'photo_time', false);

    // $Pt is an array of array
    // remove the first key (first array)
    $first_key = array_shift($Pt);

    // Add the static value to end of the array. eg: '5'
    $static_value = '5'; // define static value
    $Pt[] = array($static_value);

    // print them out
    var_dump($Pt);
}

Answer 2

UPDATE #1

Try using array_shift() like this:

foreach ($vid_pix as $vP) {
    $Pt2 = get_post_meta($vP, 'photo_time', false);
    $Pt = array_shift( $Pt2 ); // get first value
    $Pt2[] = 'static value';
    var_dump( $Pt, $Pt2 ); // test
}

UPDATE #2

If there's actually just one photo_time meta for each image/attachment (the attachment IDs are in the $vid_pix array), then this should work:

$Pt2 = [];
$n = count( $vid_pix );
for ( $i = 0, $j = 1; $i < $n; $i++, $j++ ) {
    $Pt2[] = ( $n === $j ) ? 'static value' :
        get_post_meta( $vid_pix[ $j ], 'photo_time', true );
}
echo implode( ', ', $Pt2 ); // test

UPDATE #3

Add the above ( $Pt2 ) code above /before this foreach , then add the $i => , and change the $Pt as you can see below:

foreach ($vid_pix as $i => $vP) {
  $filename = basename( get_attached_file( $vP ));
  $Pt = $Pt2[ $i ];
  ...
}

Answer 3

Why not to do it in the simplest way?

$keys = array_keys($myHashArray);
$values = array_values($myHashArray);
array_shift($keys);
array_shift($values);
$result = array_combine($keys, $values);

Please correct me if I understood it wrong.

Answer 4

you could simply proceed like this:

$static_value=25;
$array=['vp 1'=>5,'vp 2'=>10,'vp 3'=>15,'vp 4'=>20];

reset($array);//reset the internal pointer
while(false!==($key=key($array))&&null!==key($array)){//check for current key validity
    $next=next($array);//get the next value and move the pointer
    $array[$key]=$next&&isset($array[$key])?$next:$static_value;//assign the next value to the current key  if valid or the static value if false 
}


var_dump($array);

output :

array(4) {
  ["vp 1"]=>
  int(10)
  ["vp 2"]=>
  int(15)
  ["vp 3"]=>
  int(20)
  ["vp 4"]=>
  int(25)
}

Answer 5

How about ?

$new_array = array_combine( // to make an array from $keys / values
  array_keys($old_array), // use the old same keys
  array_merge( // the array containing your new values
    array_splice($old_array, 1), // remove the first element
    [$static_value] // add the static value
  )
);

Check it in live here : https://repl.it/repls/PerfectUpsetAnalysts

Answer 6

$vid_pix = get_post_meta($v_Id, 'vid_pix', false);
$i = 0;
foreach ($vid_pix as $vP) {
   if($i ==0){
continue;
}
    $Pt = get_post_meta($vP, 'photo_time', false);
    array_splice($Pt, 0, 1);
    //unset($Pt[0]);
    $Pt = get_post_meta($vP, 'photo_time', true);
    echo $Pt;

    if (last -> $Pt) { // something like this for the last value
        $Pt = '5';
    }
$i++;
 }

use this type of counter for skipping value....

Answer 7

As you already know you are getting photo_time of each vid_pix and in your question I see you need to get photo_time of next vid_pix for current vid_pix and ignore the first photo_time which is 5 in provided example and the last vid_pix (put something static instead)

[vp 1]->[5]
[vp 2]->[10]
...

I would need -

[vp 1]->[10]
[vp 2]->[15]
...

so I think its simple (I use vip_pix index as key, you can use whatever)

$pt_result = [];
for ($i = 0; $i < count($vid_pix) - 1; ++$i) {
    $pt_result[$vid_pix[$i]] = get_post_meta($vid_pix[$i+1], 'photo_time', true);
}
$pt_result[$vid_pix[$i]] = 25; //set last one statically

Answer 8

You need to shift the array outside the loop since your $Pt array has single value. Try the code given below.

$newPt = array(); // initialize new array
$vid_pix = get_post_meta($v_Id, 'vid_pix', false);

foreach ($vid_pix as $vP) {
    $Pt = get_post_meta($vP, 'photo_time', false);

    // assign to new array
    $newPt[] = $Pt;
}

// remove first value
array_shift( $newPt );

// add static value to end of the array
$static = '5';
$newPt[] = array( $static );

// print updated array
var_dump($newPt);

Hope this helps.

Answer 9

How about passing the results of get_post_meta($vP, 'photo_time', false); into a function that shifts the values and adds the static value to the end?

function shiftPt($input, $end = null) {
    $output = [];
    $prevKey = null;
    foreach ($input as $key => $value) {
        if ($lastKey) $output[$lastKey] = $value;
        $lastKey = $key;
    }
    $output[$key] = $end;
    return $output;
}

So essentially you could just wrap your existing function like so...

$pT = shiftPt(get_post_meta($vP, 'photo_time', false));

... and this would leave the last value in the array as null while shifting all of the original values up.

If you wanted to specify the final value (eg as 5 ) then you could do...

$pT = shiftPt(get_post_meta($vP, 'photo_time', false), 5);

Answer 10

You can use array_slice to remove one set of value from the array and use array_merge to merge it with the "x".

Then you just combine the keys and "new" values.

$arr = [
'vp 1'=>[5],
'vp 2'=>[10],
'vp 3'=>[15],
'vp 4'=>[20]];

$keys = array_keys($arr);
$values = array_merge(array_slice($arr, 1), ["x"]);

$new = array_combine($keys, $values);
var_dump($new);

This outputs:

array(4) {
  ["vp 1"]=>
  array(1) {
    [0]=>
    int(10)
  }
  ["vp 2"]=>
  array(1) {
    [0]=>
    int(15)
  }
  ["vp 3"]=>
  array(1) {
    [0]=>
    int(20)
  }
  ["vp 4"]=>
  string(1) "x"
}

https://3v4l.org/l7NBa