array_splice
RENOVE a portion of a given ARRAY and replace it with something else.
If $offset > 0 the start of the removed portion is at that offset from the beginning of the $input.
If $offset < 0 the start of the removed portion is at that offset from the end of the $input.
If $length is omitted, removes everything from $offset to the end of the array.
If $length = 0 no elements will be removed.
To remove everything from $offset to the end of the array when $replacement is also specified, use count($input) for $length.
If $replacement array is specified, then the removed elements are replaced with elements from this array.
If $offset and $length are such that nothing is removed, then the elements from the $replacement array are inserted in the place specified by the $offset.
Keys in the $replacement array are not preserved.
If $replacement is just one element it is not necessary to put array( ) or [ ] around it, unless the element is an array itself, an object or NULL.
<?php
arr array_splice ( arr &$input , int $offset [,
int $length = count($input) [,
mix $replacement = array() ]] )
where,
&$input = The input ARRAY
(PASSED as reference )
$offset = The position where the sequence will start
( SEE the below TABLE )
$length = The length of the sequence
( SEE the below TABLE )
$replacement = The element to replace the specified portion
( SEE the below TABLE )
?>
&$input
The input ARRAY.
$offset
The position where the sequence will start.
| VALUE |
MEANING |
| $offset > 0 |
Then the start of the removed portion is at that offset from the beginning of the $input. |
| $offset = 0 |
The sequence will start at the beginning of the $input. |
| $offset < 0 |
Then the start of the removed portion is at that offset from the end of the $input. |
| ed48 |
$length
The length of the sequence.
| VALUE |
MEANING |
| $length = count($input) |
Remove everything from $offset to the end. |
| $length > 0 |
Remove everything from $offset to the end. |
| $length = 0 |
No elements will be removed. |
| $length < 0 |
Then the end of the removed portion
will be that many elements from the end of the $input. |
| ed48 |
$replacement
To control the reorder and reset the integer array indices.
| TYPE |
MEANING |
| ARRAY |
Removed elements, replaced by elements of this array. |
| OBJECT |
Unexpected Behavior. |
| NULL |
| OTHER |
PROBABLY act as ARRAY. |
| ed48 |
EXERCISE
<?php
$arr01 = [ "HSK" => [ "HUE", "SATURATION", "BLACK" ],
"RGBc" => [ "RED", "GREEN", "BLUE" ],
"RGBt" => [ "[0,255", "[0,255]", "[0,255]" ] ];
echo 'The given $arr01:<br>';
print_r($arr01);
echo '<br><br><br>';
echo 'offset = ';
$offset01 = -48;
echo $offset01 . '<br><br>';
$slc01 = array_splice($arr01, $offset01);
echo 'array_splice($arr01, $offset01):<br>';
print_r($slc01);
echo '<br><br>';
echo 'The resulting $arr01:<br>';
print_r($arr01);
?>
EXERCISE
<?php
$arr02 = [ "HSK" => [ "HUE", "SATURATION", "BLACK" ],
"RGBc" => [ "RED", "GREEN", "BLUE" ],
"RGBt" => [ "[0,255", "[0,255]", "[0,255]" ] ];
echo 'The given $arr02:<br>';
print_r($arr02);
echo '<br><br><br>';
echo 'offset = ';
$offset02 = mt_rand(-4, 4);
echo $offset02 . '<br><br>';
echo 'length = ';
$length02 = mt_rand(-4, 4);
echo $length02 . '<br><br>';
echo 'replacement = ';
$repl02 = 'COLORS';
var_dump($repl02);
echo '<br><br>';
$slc02 = array_splice($arr02, $offset02, $length02, $repl02);
echo 'array_splice($arr02, $offset02, $length02, $repl02):<br>';
print_r($slc02);
echo '<br><br>';
echo 'The resulting $arr02:<br>';
print_r($arr02);
?>
EXERCISE
<?php
$arr03 = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
echo 'The given $arr03:<br>';
print_r($arr03);
echo '<br><br><br>';
echo 'offset = ';
$offset03 = mt_rand(-10, 10);
echo $offset03 . '<br><br>';
echo 'length = ';
$length03 = count($arr03);
echo $length03 . '<br><br>';
$repl03 = [ 'one', 'two', 'three',
'four', 'five', 'six',
'seven', 'eight' , 'nine', 'ten'];
echo 'replacement:<br>';
var_dump($repl03);
echo '<br><br>';
$slc03 = array_splice($arr03, $offset03, $length03, $repl03);
echo 'The resulting $arr03:<br>';
print_r($arr03);
?>
EXERCISE
<?php
$actdwarfs = [ 'Sneezy',
'Sleepy',
'Dopey',
'Doc',
'Happy',
'Bashful',
'Grumpy' ];
$olddwarfs = [ 'Blick',
'Flick',
'Glick',
'Snick',
'Plick',
'Whick',
'Quee' ];
echo 'The given $actdwarfs:<br>';
print_r($actdwarfs);
echo '<br><br><br>';
echo 'The given $olddwarfs:<br>';
print_r($olddwarfs);
echo '<br><br><br>';
$spldwarfs = array_splice($olddwarfs, 0, 7, $actdwarfs );
print_r($spldwarfs);
echo '<br><br><br>';
print_r($olddwarfs);
echo '<br><br><br>';
print_r($actdwarfs);
?>
EXERCISE
<?php
// The given $arr05d
$arr05d = [ "João", "Jonas", "José", "Juvenal" ];
// element to add
$arr05e = [ "JULIANA", "JULIA" ];
print_r($arr05d);
echo '<br><br>';
print_r($arr05e);
echo '<br><br>';
// initial position randomly collected
$pos05d = mt_rand(-count($arr05d), count($arr05d));
echo 'Position to consider: ' . $pos05d;
echo '<br><br>';
// calculated length, to be considered
$lnt05d = $pos05d - count($arr05e);
echo 'The lenght to consider: ' . $lnt05d;
echo '<br><br>';
$spl05d = array_splice($arr05d, $pos05d, $lnt05d, $arr05e);
// element to remove
echo 'The element to be removed:<br>';
print_r($spl05d);
echo '<br><br>';
// resulting ARRAY
echo 'The resulting $arr05d:<br>';
print_r($arr05d);
?>
EXERCISE
<?php
/*
* Function is implemented in ext/standard/array.c
*/
echo "Testing array_splice() basic operations.";
echo "<br><br>Test truncation:<br>";
$input = array("red", "green", "blue", "yellow");
var_dump (array_splice($input, 2));
echo '<br><br>';
var_dump ($input);
// $input is now array("red", "green")
echo "<br><br><br>Test truncation with null length:<br>";
$input = array("red", "green", "blue", "yellow");
var_dump (array_splice($input, 2, null));
echo '<br><br>';
var_dump ($input);
// $input is now array("red", "green")
echo "<br><br><br>Test removing entries from the middle:<br>";
$input = array("red", "green", "blue", "yellow");
var_dump (array_splice($input, 1, -1));
echo '<br><br>';
var_dump ($input);
// $input is now array("red", "yellow")
echo "<br><br><br>Test substitution at end:<br>";
$input = array("red", "green", "blue", "yellow");
var_dump (array_splice($input, 1, count($input), "orange"));
echo '<br><br>';
var_dump ($input);
// $input is now array("red", "orange")
$input = array("red", "green", "blue", "yellow");
var_dump (array_splice($input, -1, 1,
array("black", "maroon")));
echo '<br><br>';
var_dump ($input);
// $input is now array("red", "green",
// "blue", "black", "maroon")
echo "<br><br><br>Test insertion:<br>";
$input = array("red", "green", "blue", "yellow");
var_dump (array_splice($input, 3, 0, "purple"));
echo '<br><br>';
var_dump ($input);
// $input is now array("red", "green",
// "blue", "purple", "yellow");
?>
EXERCISE
<?php
/*
* Function is implemented in ext/standard/array.c
*/
echo "Test behaviour when input array
is in a reference set.";
$input_array=array (array(1,2));
$input_array[]=&$input_array[0];
var_dump (array_splice ($input_array[0],1,1));
var_dump ($input_array);
echo "<br><br>Test behaviour of input
arrays containing references:<br>";
/*
* There are three regions to test:,
* before cut, the cut and after the cut.
* For reach we check a plain value,
* a reference value with integer key and a
* reference value with a string key.
*/
$numbers=array(0,1,2,3,4,5,6,7,8,9,10,11,12);
$input_array=array(0,1,&$numbers[2],
"three"=>&$numbers[3],
4,
&$numbers[5],
"six"=>&$numbers[6],
7,
&$numbers[8],
"nine"=>&$numbers[9]);
var_dump (array_splice ($input_array,4,3));
var_dump ($input_array);
echo "<br><br>Test behaviour of replacement
array containing references:<br>";
$three=3;
$four=4;
$input_array=array (0,1,2);
$b=array(&$three,"fourkey"=>&$four);
array_splice ($input_array,-1,1,$b);
var_dump ($input_array);
echo "<br><br>Test behaviour of replacement
which is part of reference set:<br>";
$int=3;
$input_array=array (1,2);
$b=&$int;
array_splice ($input_array,-1,1,$b);
var_dump ($input_array);
?>
EXERCISE
<?php
/*
* Function is implemented in ext/standard/array.c
*/
echo "array_splice() function : usage variations -
lengths and offsets.<br><br>";
function test_splice ($offset, $length)
{
echo "<br><br>No replacement:<br>";
$input_array=array(0,1,2,3,4,5);
var_dump (array_splice ($input_array,
$offset,$length));
var_dump ($input_array);
echo "<br><br>With replacement:<br>";
$input_array=array(0,1,2,3,4,5);
var_dump (array_splice ($input_array,
$offset,
$length,
array ("A","B","C")));
echo "<br><br>";
var_dump ($input_array);
echo '<br><br><br>';
}
echo "01. absolute offset - absolute length -
cut from beginning.";
test_splice (0,2);
echo "02. absolute offset - absolute length -
cut from middle.";
test_splice (2,2);
echo "03. absolute offset - absolute length -
cut from end.";
test_splice (4,2);
echo "04. absolute offset - absolute length -
attempt to cut past end.";
test_splice (4,4);
echo "05. absolute offset - absolute length -
cut everything.";
test_splice (0,7);
echo "06. absolute offset - absolute length -
cut nothing.";
test_splice (3,0);
echo "07. absolute offset - relative length -
cut from beginning.";
test_splice (0,-4);
echo "08. absolute offset - relative length -
cut from middle.";
test_splice (2,-2);
echo "09. absolute offset - relative length -
attempt to cut form before beginning .";
test_splice (0,-7);
echo "10. absolute offset - relative length -
cut nothing.";
test_splice (2,-7);
echo "11. relative offset - absolute length -
cut from beginning.";
test_splice (-6,2);
echo "12. relative offset - absolute length -
cut from middle.";
test_splice (-4,2);
echo "13. relative offset - absolute length -
cut from end.";
test_splice (-2,2);
echo "14. relative offset - absolute length -
attempt to cut past end.";
test_splice (-2,4);
echo "15. relative offset - absolute length -
cut everything.";
test_splice (-6,6);
echo "16. relative offset - absolute length -
cut nothing.";
test_splice (-6,0);
echo "17. relative offset - relative length -
cut from beginning.";
test_splice (-6,-4);
echo "18. relative offset - relative length -
cut from middle.";
test_splice (-4,-2);
echo "19. relative offset - relative length -
cut nothing.";
test_splice (-4,-7);
?>
EXERCISE
<?php
/*
* Function is implemented in ext/standard/array.c
*/
function test_splice ($replacement)
{
$input_array=array(0,1);
var_dump (array_splice ($input_array,2,0,$replacement));
var_dump ($input_array);
echo '<br><br>';
}
test_splice (2);
test_splice (2.1);
test_splice (true);
//file type resource
$file_handle = fopen(__FILE__, "r");
test_splice ($file_handle);
fclose($file_handle);
?>