Foreach不适用于两个数组

Question

I have an array

$assid=Array
(
    [0] => Array
        (
            [0] => 6
            [1] => 2
            [2] => 3
        )

    [1] => Array
        (
            [0] => 4
            [1] => 5
            [2] => 6
        )

    [2] => Array
        (
            [0] => 6
        )

    [3] => Array
        (
            [0] => 2
            [1] => 3
        )

)

and

$key1=Array
    (
        [0] => 0
        [1] => 1
        [2] => 2
        [3] => 3
    )

Here $key1 means index of $assid

And a foreach loop

 @foreach($roles as $id=>$name)



<option value="{{$id}}"@if(in_array($id, $assid))selected="selected"@endif>{{$name}}</option>

   @endforeach

Here roles have 12 values.so array will iterate 12 times.my problem is that I want to append $assid[0],[1],[2],[3] so i $key1 values with foreach so I tried

$a=0;
     @foreach($roles as $id=>$name)



    <option value="{{$id}}"@if(in_array($id, $assid[$a]))selected="selected"@endif>{{$name}}</option>
    <?php  $a++;?>
       @endforeach

Because $key1 array as only index 0 1 2 3.so i need $a should be incremented as 0 to 3 inside foreach loop 12 iterations are there so after 3 it shows undefined index 4.i didn't get a proper solution. please help me.Please

Answer 1

$a=0;
 @foreach($roles as $id=>$name)
<option value="{{$id}}"@if(in_array($id, $assid[$a]))selected="selected"@endif>{{$name}}</option>
<?php  $a++;?
 if(a>4){
 a = 0;
   }>
   @endforeach

it make value zero if you are more then 4 so it start agin from zero

Answer 2

If i understand your problem you are looking for this stuff...Try this :-

$assid=Array
(
[0] => 0
[1] => 1
[2] => 2
[3] => 3
)
$roles=Array
(
[0] => 0
[1] => 1
[2] => 2
[3] => 3
[4] => 4
[5] => 6
[6] => 7
[8] => 8
[9] => 9
[10] => 10
[11] => 11

)
@foreach($roles as $id => $name)
  @if(isset($assid[$id]))
    <option value="{{$id}}"@if(in_array($id, $assid))selected="selected"@endif>{{$name}}</option>
  @else 
    <option value="{{$id}}">{{$name}}</option>
  @endif
@endforeach

Hope it helps!

Answer 3

Possibly it works as expected.

$a=0;
@foreach($roles as $id=>$name)
<?php if($a>3) $a=0; ?>
<option value="{{$id}}"@if(in_array($id, $assid[$a]))selected="selected"@endif>{{$name}}</option>
<?php  $a++; ?>
@endforeach

Answer 4

You need to round-robin back from N to 0 . Using an index that is modulo N + 1 of the counter guarantees this.

To round-robin through the first 3 items of an array, where N=2 because arrays have zero-based indexing, we'll take modulo 3

@php ($a = 0)

@foreach($roles as $id=>$name)
   <option
     value="{{$id}}" 
     @if(in_array($id, $assid[$a % 3])) 
         selected="selected"
     @endif
   >{{ $name }}</option>

   @php ($a = $a + 1)
@endforeach