Array offset without losing values

Question

After looking through PHP.net documentation for hours, is this the best way to offset an array from start to finish by using array_slice() with array_merge()?

For example: $array = array(1,2,3,4) to offset by 2 to get return $array = array(3,4,1,2).

Here's the code I'm using it in:

 $team = 2;
 $course = array(
 array('title'=>1, 'hole'=> 'h01', 'shot1'=>'value="-3"', 'shot2'=>'value="-2"', 'shot3'=>'value="-1"', 'shot4'=>'value="0"', 'shot5'=>'disabled="disabled"'),
 array('title'=>2, 'hole'=> 'h02', 'shot1'=>'value="-4"', 'shot2'=>'value="-3"', 'shot3'=>'value="-2"', 'shot4'=>'value="-1"', 'shot5'=>'value="0"'),
 array('title'=>3, 'hole'=> 'h03', 'shot1'=>'value="-3"', 'shot2'=>'value="-2"', 'shot3'=>'value="-1"', 'shot4'=>'value="0"', 'shot5'=>'disabled="disabled"'),
 array('title'=>4, 'hole'=> 'h04', 'shot1'=>'value="-2"', 'shot2'=>'value="-1"', 'shot3'=>'value="0"', 'shot4'=>'disabled="disabled"', 'shot5'=>'disabled="disabled"'),
 array('title'=>5, 'hole'=> 'h05', 'shot1'=>'value="-4"', 'shot2'=>'value="-3"', 'shot3'=>'value="-2"', 'shot4'=>'value="-1"', 'shot5'=>'value="0"')
 );
 $array1 = array_slice($course, $team);
 $array2 = array_slice($course, 0, $team);
 $merged = array_merge($array1, $array2);
}

Answer 1

If you don't mind modifying the original array, you can shorten the (perfectly adequate code you have) with this:

$head = array_splice($course, 0, $team); // remove and return first $team elements
$merged = array_merge($course, $head); // append them to the end

You should be able to omit the temporary $head array by inserting the array_splice call into the array_merge call at the cost of a little code clarity. Try it out to make sure the order of operations is correct.

$merged = array_merge($course, array_splice($course, 0, $team));

Edit: If you're doing this once per team you can use a loop with array_shift to remove the first element and array_push to place it at the end:

for ($team = 0; $team < $numTeams; $team++) {
 array_push($course, array_shift($course));
 // use $course...
}

• Conor: I'm just trying to loop 18 arrays but have different starting arrays based on team value. So for example, $team = 5 then output $array = array(array(5),array(6),array(7),array(8),array(9),array(10),array(11),array(12),array(13),array(14),array(15),array(16),array(17),array(18),array(1),array(2),array(3),array(4));
• David Harkness: Do you have 18 different starting arrays? Or are you taking the same array and doing the above for $team = 1, $team = 2, $team = 3, etc?
• Conor: The latter, one array with 18 different orders based on team ID.
• David Harkness: @Conor In that case see my edit.

Answer 2

Here's what worked best for me.

$team = 2;
$start = $team - 1;
$course = array(
array('title'=>1, 'hole'=> 'h01', 'shot1'=>'value="-3"', 'shot2'=>'value="-2"', 'shot3'=>'value="-1"', 'shot4'=>'value="0"', 'shot5'=>'disabled="disabled"'),
array('title'=>2, 'hole'=> 'h02', 'shot1'=>'value="-4"', 'shot2'=>'value="-3"', 'shot3'=>'value="-2"', 'shot4'=>'value="-1"', 'shot5'=>'value="0"'),
array('title'=>3, 'hole'=> 'h03', 'shot1'=>'value="-3"', 'shot2'=>'value="-2"', 'shot3'=>'value="-1"', 'shot4'=>'value="0"', 'shot5'=>'disabled="disabled"'),
array('title'=>4, 'hole'=> 'h04', 'shot1'=>'value="-2"', 'shot2'=>'value="-1"', 'shot3'=>'value="0"', 'shot4'=>'disabled="disabled"', 'shot5'=>'disabled="disabled"'),
array('title'=>5, 'hole'=> 'h05', 'shot1'=>'value="-4"', 'shot2'=>'value="-3"', 'shot3'=>'value="-2"', 'shot4'=>'value="-1"', 'shot5'=>'value="0"')
);
$slice1 = array_slice($course, $start);
$slice2 = array_slice($course, 0, $start);
$merged = array_merge($slice1, $slice2);