PHP - Make nested if statement output shorter - php

I often end up with something like below:
<?php
foreach($items as $item) {
if($item['key']) {
echo 'Alright';
if($item['value']) {
echo 'Inside';
} else {
$output[] = [
$item['data1'],
$item['data2'],
];
}
} else {
$output[] = [
$item['data1'],
$item['data2'],
];
}
}
print_r($output);
As you can see I use nested if statements. What nags me is that I have the same output in both else. I would prefer keep things DRY.
So, if I'm in an else statement anywhere within the foreach, I want to output the same results.
Update
My real code is a bit more complex.
foreach($out as $i => $data) {
$dayshort = mb_substr($data[0], 0, 3);
if(isset($out[$i+1][0])) {
$future = $out[$i+1][0];
$daykey = array_search($data[0], $weekdays);
$nextday = $weekdays[$daykey + 1];
if($nextday != $future) {
$backkey = array_search($future, $weekdays) - 1;
$backname = mb_substr($weekdays[$backkey], 0, 3);
$final[] = [
$dayshort . ' - ' . $backname,
$data[1],
$data[2]
];
} else {
$final[] = [
$data[0],
$data[1],
$data[2]
];
}
} else {
$final[] = [
$data[0],
$data[1],
$data[2]
];
}
}
Now I've setup a repo here with the complete code: https://github.com/jenstornell/daybreaker

foreach($out as $i => $data) {
$dayshort = mb_substr($data[0], 0, 3);
$result = $data[0]; /* default case value */
if (isset($out[$i + 1][0])) {
$future = $out[$i + 1][0];
$daykey = array_search($data[0], $weekdays);
$nextday = $weekdays[$daykey + 1];
if ($nextday != $future) {
$backkey = array_search($future, $weekdays) - 1;
$backname = mb_substr($weekdays[$backkey], 0, 3);
$result = $dayshort.' - '.$backname; /* overrite here */
}
}
/* just once */
$final[] = [
$result,
$data[1],
$data[2]
];
}

I think it's more simpler
<?php
foreach($items as $item) {
if($item['key']) {
echo 'Alright';
if($item['value'])
echo 'Inside';
}
$output[] = [
$item['data1'],
$item['data2'],
];
}

You can initialize a variable for else part like
$is_false=0;
Set it to "1" once you are in else block and at last step check this variable and if it is "1" set the outout or else block code.
Refer the code below.
<?php
foreach($items as $item) {
if($item['key']) {
echo 'Alright';
if($item['value']) {
echo 'Inside';
} else {
$is_false = 1;
}
}else{
$is_false = 1;
}
if($is_false==1){
$output[] = [
$item['data1'],
$item['data2'],
];
}
}
print_r($output);

Related

How do you get the next key in an associative array php [duplicate]

I have a foreach loop and I want to see if there is a next element in the loop so I can compare the current element with the next. How can I do this? I've read about the current and next functions but I can't figure out how to use them.
A unique approach would be to reverse the array and then loop. This will work for non-numerically indexed arrays as well:
$items = array(
'one' => 'two',
'two' => 'two',
'three' => 'three'
);
$backwards = array_reverse($items);
$last_item = NULL;
foreach ($backwards as $current_item) {
if ($last_item === $current_item) {
// they match
}
$last_item = $current_item;
}
If you are still interested in using the current and next functions, you could do this:
$items = array('two', 'two', 'three');
$length = count($items);
for($i = 0; $i < $length - 1; ++$i) {
if (current($items) === next($items)) {
// they match
}
}
#2 is probably the best solution. Note, $i < $length - 1; will stop the loop after comparing the last two items in the array. I put this in the loop to be explicit with the example. You should probably just calculate $length = count($items) - 1;
You could probably use while loop instead of foreach:
while ($current = current($array) )
{
$next = next($array);
if (false !== $next && $next == $current)
{
//do something with $current
}
}
If the indexes are continuous:
foreach ($arr as $key => $val) {
if (isset($arr[$key+1])) {
echo $arr[$key+1]; // next element
} else {
// end of array reached
}
}
As php.net/foreach points out:
Unless the array is referenced, foreach operates on a copy of the specified array and not the array itself. foreach has some side effects on the array pointer. Don't rely on the array pointer during or after the foreach without resetting it.
In other words - it's not a very good idea to do what you're asking to do. Perhaps it would be a good idea to talk with someone about why you're trying to do this, see if there's a better solution? Feel free to ask us in ##PHP on irc.freenode.net if you don't have any other resources available.
You could get the keys/values and index
<?php
$a = array(
'key1'=>'value1',
'key2'=>'value2',
'key3'=>'value3',
'key4'=>'value4',
'key5'=>'value5'
);
$keys = array_keys($a);
foreach(array_keys($keys) as $index ){
$current_key = current($keys); // or $current_key = $keys[$index];
$current_value = $a[$current_key]; // or $current_value = $a[$keys[$index]];
$next_key = next($keys);
$next_value = $a[$next_key] ?? null; // for php version >= 7.0
echo "{$index}: current = ({$current_key} => {$current_value}); next = ({$next_key} => {$next_value})\n";
}
result:
0: current = (key1 => value1); next = (key2 => value2)
1: current = (key2 => value2); next = (key3 => value3)
2: current = (key3 => value3); next = (key4 => value4)
3: current = (key4 => value4); next = (key5 => value5)
4: current = (key5 => value5); next = ( => )
if its numerically indexed:
foreach ($foo as $key=>$var){
if($var==$foo[$key+1]){
echo 'current and next var are the same';
}
}
The general solution could be a caching iterator. A properly implemented caching iterator works with any Iterator, and saves memory. PHP SPL has a CachingIterator, but it is very odd, and has very limited functionality. However, you can write your own lookahead iterator like this:
<?php
class NeighborIterator implements Iterator
{
protected $oInnerIterator;
protected $hasPrevious = false;
protected $previous = null;
protected $previousKey = null;
protected $hasCurrent = false;
protected $current = null;
protected $currentKey = null;
protected $hasNext = false;
protected $next = null;
protected $nextKey = null;
public function __construct(Iterator $oInnerIterator)
{
$this->oInnerIterator = $oInnerIterator;
}
public function current()
{
return $this->current;
}
public function key()
{
return $this->currentKey;
}
public function next()
{
if ($this->hasCurrent) {
$this->hasPrevious = true;
$this->previous = $this->current;
$this->previousKey = $this->currentKey;
$this->hasCurrent = $this->hasNext;
$this->current = $this->next;
$this->currentKey = $this->nextKey;
if ($this->hasNext) {
$this->oInnerIterator->next();
$this->hasNext = $this->oInnerIterator->valid();
if ($this->hasNext) {
$this->next = $this->oInnerIterator->current();
$this->nextKey = $this->oInnerIterator->key();
} else {
$this->next = null;
$this->nextKey = null;
}
}
}
}
public function rewind()
{
$this->hasPrevious = false;
$this->previous = null;
$this->previousKey = null;
$this->oInnerIterator->rewind();
$this->hasCurrent = $this->oInnerIterator->valid();
if ($this->hasCurrent) {
$this->current = $this->oInnerIterator->current();
$this->currentKey = $this->oInnerIterator->key();
$this->oInnerIterator->next();
$this->hasNext = $this->oInnerIterator->valid();
if ($this->hasNext) {
$this->next = $this->oInnerIterator->current();
$this->nextKey = $this->oInnerIterator->key();
} else {
$this->next = null;
$this->nextKey = null;
}
} else {
$this->current = null;
$this->currentKey = null;
$this->hasNext = false;
$this->next = null;
$this->nextKey = null;
}
}
public function valid()
{
return $this->hasCurrent;
}
public function hasNext()
{
return $this->hasNext;
}
public function getNext()
{
return $this->next;
}
public function getNextKey()
{
return $this->nextKey;
}
public function hasPrevious()
{
return $this->hasPrevious;
}
public function getPrevious()
{
return $this->previous;
}
public function getPreviousKey()
{
return $this->previousKey;
}
}
header("Content-type: text/plain; charset=utf-8");
$arr = [
"a" => "alma",
"b" => "banan",
"c" => "cseresznye",
"d" => "dio",
"e" => "eper",
];
$oNeighborIterator = new NeighborIterator(new ArrayIterator($arr));
foreach ($oNeighborIterator as $key => $value) {
// you can get previous and next values:
if (!$oNeighborIterator->hasPrevious()) {
echo "{FIRST}\n";
}
echo $oNeighborIterator->getPreviousKey() . " => " . $oNeighborIterator->getPrevious() . " -----> ";
echo "[ " . $key . " => " . $value . " ] -----> ";
echo $oNeighborIterator->getNextKey() . " => " . $oNeighborIterator->getNext() . "\n";
if (!$oNeighborIterator->hasNext()) {
echo "{LAST}\n";
}
}
You could get the keys of the array before the foreach, then use a counter to check the next element, something like:
//$arr is the array you wish to cycle through
$keys = array_keys($arr);
$num_keys = count($keys);
$i = 1;
foreach ($arr as $a)
{
if ($i < $num_keys && $arr[$keys[$i]] == $a)
{
// we have a match
}
$i++;
}
This will work for both simple arrays, such as array(1,2,3), and keyed arrays such as array('first'=>1, 'second'=>2, 'thrid'=>3).
A foreach loop in php will iterate over a copy of the original array, making next() and prev() functions useless. If you have an associative array and need to fetch the next item, you could iterate over the array keys instead:
foreach (array_keys($items) as $index => $key) {
// first, get current item
$item = $items[$key];
// now get next item in array
$next = $items[array_keys($items)[$index + 1]];
}
Since the resulting array of keys has a continuous index itself, you can use that instead to access the original array.
Be aware that $next will be null for the last iteration, since there is no next item after the last. Accessing non existent array keys will throw a php notice. To avoid that, either:
Check for the last iteration before assigning values to $next
Check if the key with index + 1 exists with array_key_exists()
Using method 2 the complete foreach could look like this:
foreach (array_keys($items) as $index => $key) {
// first, get current item
$item = $items[$key];
// now get next item in array
$next = null;
if (array_key_exists($index + 1, array_keys($items))) {
$next = $items[array_keys($items)[$index + 1]];
}
}
$next_data = $data;
$prev_key = null;
$prev_value = null;
foreach($data as $key => $value)
{
array_shift($next_data);
$next_key = key($next_data);
$next_value = $next_data[$next_key] ?? null;
// Do something here...
$prev_key = $key;
$prev_value = $value;
}
or if the array is associative then you could use current() similar to Andrei Krasutski's solution and key()
$values = [];
array_push($values, ["XYZ"=>100]);
array_push($values, ["ABC"=>10]);
array_push($values, ["XYZ"=>130]);
array_push($values, ["DEF"=>4]);
array_push($values, ["XYZ"=>5]);
$count = count($values);
foreach ($values as $index => $currentValue) {
if ($index < $count - 1) {
$nextValue = $values[$index + 1];
echo key($currentValue) . "=" . current($currentValue) . " followed by " . key($nextValue) . "/" . current($nextValue) . "<br>\n";
} else {
echo key($currentValue) . "=" . current($currentValue);
}
}
See https://onlinephp.io/c/dc58d for a running example.
or if the array is using named pairs:
$values = [];
array_push($values, ["type"=>"XYZ", "value"=>100]);
array_push($values, ["type"=>"ABC", "value"=>10]);
array_push($values, ["type"=>"XYZ", "value"=>130]);
array_push($values, ["type"=>"DEF", "value"=>"Lorem"]);
array_push($values, ["type"=>"XYZ", "value"=>5]);
$count = count($values);
foreach ($values as $index => $currentValue) {
if ($index < $count - 1) {
$nextValue = $values[$index + 1];
echo $currentValue['type'] . "=" . $currentValue['value']
. " followed by " . $nextValue['type'] . "/" . $nextValue['value'] . "<br>\n";
} else {
echo $currentValue['type'] . "=" . $currentValue['value'];
}
}

how to get each user list in array

public function getChildren($parent, $level=0,$getlevel=array()) {
$criteria = new CDbCriteria;
$criteria->condition='referred_by_user_id=:id';
$criteria->params=array(':id'=>$parent);
$count = array(0=>0);
$model = $this->findAll($criteria);
// $levelcount = array();
$user=User::model()->findbypk(Yii::app()->user->id);
if($user->level!=$level)
{
foreach ($model as $key) {
$count[0]++;
$index=1;
// echo str_repeat(' — ', $level) . $key->name . "<br />";
$children= $this->getChildren($key->id, $level+1);
// pr($children);die;
foreach ($children as $child)
{
// pr($child);
if ($child==0)
continue;
if (isset($count[$index]))
$count[$index] += $child;
else
$count[$index] = $child;
$index++;
}
}
}
return $count;
}
I can output only the number of users. How do I get the user id for each level in an array?
I think the problem is you must make $index variable outside of for
I made something similiar a while ago:
public static function getChildren($idParent) {
$elem = [];
$childrens = Arbol::model()->findAll("estado = 1 and id_parent = " . $idParent . ' ORDER BY level');
foreach ($childrens as $key => $child) {
$persona = Persona::model()->findbyPk($child->id_child);
if ((int) $persona->id_superior === $idParent) {
$nombre = explode(" ", $persona->nombres);
$elem[$key] = [
"id" => $persona->id_persona,
"image" => Yii::app()->baseUrl . '/images/user-icon' . ($persona->pago_inscripcion ? '-activo.png' : '.png'),
"text" => [
'title' => $nombre[0] . ' ' . substr($persona->apellido_paterno, 0, 1) . '.'
]
];
} else {
$keySUperior = array_search($persona->id_superior, array_column($elem, "id"));
if (is_int($keySUperior)) {
$elem[$keySUperior]["children"] = self::getChildren((int) $persona->id_superior);
}
}
}
return $elem;
}
I hope i give you any help

PHP sort array by same value twice

I have array with show names like this:
$shows = array('morning_show_15_02_2014_part2.mp3',
'morning_show_15_02_2014_part1.mp3',
'morning_show_14_02_2014_part2.mp3',
'morning_show_14_02_2014_part1.mp3',
'morning_show_13_02_2014_part2.mp3',
'morning_show_13_02_2014_part1.mp3');
So the list look like:
morning_show_15_02_2014_part2.mp3
morning_show_15_02_2014_part1.mp3
morning_show_14_02_2014_part2.mp3
morning_show_14_02_2014_part1.mp3
morning_show_13_02_2014_part2.mp3
morning_show_13_02_2014_part1.mp3
This is what i get when i loop the directory.
But the list should look like this:
morning_show_15_02_2014_part1.mp3
morning_show_15_02_2014_part2.mp3
morning_show_14_02_2014_part1.mp3
morning_show_14_02_2014_part2.mp3
morning_show_13_02_2014_part1.mp3
morning_show_13_02_2014_part2.mp3
Still ordered by date, but part 1 is first and then comes part 2.
How can i get this list into right order?
Thank you for any help!
Resolved!
Code is prett nasty but i got what i was looking for:
public function getMp3ListAsJSONArray() {
$songs = array();
$mp3s = glob($this->files_path . '/*.mp3');
foreach ($mp3s as $key => $mp3Source) {
$mp3Source = basename($mp3Source);
$mp3Title = substr($mp3Source, 4);
$mp3Title = substr($mp3Title, 0, -4);
$mp3Title = basename($mp3Source, ".mp3");
$mp3Title = str_replace('_', ' ', $mp3Title);
$mp3Title = ucfirst($mp3Title);
$songs[$key]['title'] = $mp3Title;
$songs[$key]['mp3'] = urldecode($this->files_url . '/' . $mp3Source);
}
rsort($songs);
$pairCounter = 1;
$counter = 0;
foreach ($songs as $key => $value) {
$playlist[$pairCounter][] = $value;
$counter = $counter + 1;
if($counter == 2) {
$pairCounter = $pairCounter + 1;
$counter = 0;
}
}
foreach ($playlist as $show) {
$finalList[] = $show[1];
$finalList[] = $show[0];
}
$finalList = json_encode($finalList);
return $finalList;
}
Output is like i described in the topic.
Try to use array sort
Here is an example for you
http://techyline.com/php-sorting-array-with-unique-value/
You must definitely write your own string comparision function. Remember that you have 2 different comparisons. The first compares the first parts for the filenames as strings. The second part compares the numbers, where 20 comes after 2. This is a natural number sorting for the second part. The third part is after the last dot in the filename. This will be ignored.
<?php
function value_compare($a, $b) {
$result = 0;
$descending = TRUE;
$positionA = strpos($a, 'part');
$positionB = strpos($b, 'part');
if ($positionA === $positionB) {
$compareFirstPart = substr_compare($a, $b, 0, $positionA + 1);
if ($compareFirstPart === 0) {
$length = 0;
$offset = $positionA + strlen('part');
$positionDotA = strrpos($a, '.');
$positionDotB = strrpos($b, '.');
$part2A = '';
$part2B = '';
if ($positionDotA !== FALSE) {
$part2A = substr($a, $offset, $positionDotA);
} else {
$part2A = substr($a, $offset);
}
if ($positionDotB !== FALSE) {
$part2B = substr($b, $offset, $positionDotB);
} else {
$part2B = substr($b, $offset);
}
$result = strnatcmp($part2A, $part2B);
} else {
$result = $compareFirstPart;
if ($descending) {
$result = -$result;
}
}
}
return $result;
}
$shows = array('morning_show_15_02_2014_part2.mp3', 'morning_show_15_02_2014_part1.mp3', 'morning_show_14_02_2014_part2.mp3', 'morning_show_14_02_2014_part1.mp3', 'morning_show_13_02_2014_part2.mp3', 'morning_show_13_02_2014_part1.mp3');
usort($shows, 'value_compare');
var_dump($shows);
?>

PHP - counting problem algorithm

I need to get all the combinations and permutations of an array of array of values. See snippet for example:
$a = array(
1,
2
);
$b = array(
'foo',
'bar'
);
$params = array();
$params[] = $a;
$params[] = $b;
// What to do to $params so I can get the following combinations/permutations?
// 1,foo
// 2,foo
// 1,bar
// 2,bar
// foo,1
// bar,1
// foo,2
// bar,2
Keep in mind that the $params can be any size and the items in it can also be any size.
function all($array, $partial, &$result) {
if ($array == array()) {
$result[] = implode(',', $partial);
return;
}
for($i=0; $i<count($array);$i++) {
$e = $array[$i];
$a = $array;
array_splice($a, $i, 1);
foreach($e as $v) {
$p = $partial;
$p[] = $v;
all($a, $p, $result);
}
}
}
Test:
$a = array(1, 2, 3);
$b = array('foo', 'bar');
$c = array('a', 'b');
$params = array($a, $b, $c);
$result = array();
all($params, array(), $result);
print_r($result);
Note: if there is a chance for duplicates (arrays contain the same values) you can check for duplicates before inserting into the $result.
Here is my solution. It should work with any number of associative arrays, even if they contained nested associative arrays.
<?php
$a = array(1,2,3);
$b = array('foo','bar','baz', array('other','other2',array('other3','other4')));
$params = array();
$params[] = $a;
$params[] = $b;
$elements = array();
foreach($params as $param) {
addElement($param,$elements);
}
function addElement($arg,&$result) {
if(!is_array($arg)) {
$result[] = $arg;
} else {
foreach($arg as $argArray) {
addElement($argArray,$result);
}
}
}
for($i=0; $i<count($elements); $i++) {
$curElement = $elements[$i];
for($j=0; $j<count($elements); $j++) {
if($elements[$j] != $curElement) {
$final_results[] = $curElement.','.$elements[$j];
}
}
}
print_r($final_results);
?>
http://codepad.viper-7.com/XEAKFM
Here's a possible solution codepad...
$array = array(
0 => array(
'foo',
'bar'
),
1 => array(
1,
2,
3
),
2 => array(
'x',
'y',
'z'
),
3 => array(
7,
8,
9
)
);
array_permutations($array, $permutations);
print_r($permutations);
public function array_permutations($array, &$permutations, $current_key = 0, $current_subkey = 0)
{
if(!isset($array[$current_key][$current_subkey]))
{
return;
}
$current_val = $array[$current_key][$current_subkey];
foreach($array as $array_key => $row)
{
foreach($row as $row_key => $sub_val)
{
if($array_key === $current_key)
{
if($row_key !== $current_subkey)
{
$permutations[] = $current_val . ', ' . $sub_val;
}
}
else
{
$permutations[] = $current_val . ', ' . $sub_val;
}
}
}
$next_key = ($current_subkey == (count($array[$current_key]) - 1)) ? $current_key + 1 : $current_key;
$next_subkey = ($next_key > $current_key) ? 0 : $current_subkey + 1;
array_permutations($array, $permutations, $next_key, $next_subkey);
}
Try this out, hope this helps
$a = array(
1,
2,
4
);
$b = array(
'foo',
'bar',
'zer'
);
$c = array(
'aaa',
'bbb'
);
$params = array();
$params[] = $a;
$params[] = $b;
$params[] = $c;
$sizeofp = count($params);
for($i=0 ; $i < $sizeofp ; $i++){
foreach ($params[$i] as $paramA) {
for($j=0 ; $j < $sizeofp ; $j++){
if($j == $i){
continue;
}
foreach($params[$j] as $paramB){
echo "\n".$paramA.",".$paramB;
}
}
}
}

Get next element in foreach loop

I have a foreach loop and I want to see if there is a next element in the loop so I can compare the current element with the next. How can I do this? I've read about the current and next functions but I can't figure out how to use them.
A unique approach would be to reverse the array and then loop. This will work for non-numerically indexed arrays as well:
$items = array(
'one' => 'two',
'two' => 'two',
'three' => 'three'
);
$backwards = array_reverse($items);
$last_item = NULL;
foreach ($backwards as $current_item) {
if ($last_item === $current_item) {
// they match
}
$last_item = $current_item;
}
If you are still interested in using the current and next functions, you could do this:
$items = array('two', 'two', 'three');
$length = count($items);
for($i = 0; $i < $length - 1; ++$i) {
if (current($items) === next($items)) {
// they match
}
}
#2 is probably the best solution. Note, $i < $length - 1; will stop the loop after comparing the last two items in the array. I put this in the loop to be explicit with the example. You should probably just calculate $length = count($items) - 1;
You could probably use while loop instead of foreach:
while ($current = current($array) )
{
$next = next($array);
if (false !== $next && $next == $current)
{
//do something with $current
}
}
If the indexes are continuous:
foreach ($arr as $key => $val) {
if (isset($arr[$key+1])) {
echo $arr[$key+1]; // next element
} else {
// end of array reached
}
}
As php.net/foreach points out:
Unless the array is referenced, foreach operates on a copy of the specified array and not the array itself. foreach has some side effects on the array pointer. Don't rely on the array pointer during or after the foreach without resetting it.
In other words - it's not a very good idea to do what you're asking to do. Perhaps it would be a good idea to talk with someone about why you're trying to do this, see if there's a better solution? Feel free to ask us in ##PHP on irc.freenode.net if you don't have any other resources available.
You could get the keys/values and index
<?php
$a = array(
'key1'=>'value1',
'key2'=>'value2',
'key3'=>'value3',
'key4'=>'value4',
'key5'=>'value5'
);
$keys = array_keys($a);
foreach(array_keys($keys) as $index ){
$current_key = current($keys); // or $current_key = $keys[$index];
$current_value = $a[$current_key]; // or $current_value = $a[$keys[$index]];
$next_key = next($keys);
$next_value = $a[$next_key] ?? null; // for php version >= 7.0
echo "{$index}: current = ({$current_key} => {$current_value}); next = ({$next_key} => {$next_value})\n";
}
result:
0: current = (key1 => value1); next = (key2 => value2)
1: current = (key2 => value2); next = (key3 => value3)
2: current = (key3 => value3); next = (key4 => value4)
3: current = (key4 => value4); next = (key5 => value5)
4: current = (key5 => value5); next = ( => )
if its numerically indexed:
foreach ($foo as $key=>$var){
if($var==$foo[$key+1]){
echo 'current and next var are the same';
}
}
The general solution could be a caching iterator. A properly implemented caching iterator works with any Iterator, and saves memory. PHP SPL has a CachingIterator, but it is very odd, and has very limited functionality. However, you can write your own lookahead iterator like this:
<?php
class NeighborIterator implements Iterator
{
protected $oInnerIterator;
protected $hasPrevious = false;
protected $previous = null;
protected $previousKey = null;
protected $hasCurrent = false;
protected $current = null;
protected $currentKey = null;
protected $hasNext = false;
protected $next = null;
protected $nextKey = null;
public function __construct(Iterator $oInnerIterator)
{
$this->oInnerIterator = $oInnerIterator;
}
public function current()
{
return $this->current;
}
public function key()
{
return $this->currentKey;
}
public function next()
{
if ($this->hasCurrent) {
$this->hasPrevious = true;
$this->previous = $this->current;
$this->previousKey = $this->currentKey;
$this->hasCurrent = $this->hasNext;
$this->current = $this->next;
$this->currentKey = $this->nextKey;
if ($this->hasNext) {
$this->oInnerIterator->next();
$this->hasNext = $this->oInnerIterator->valid();
if ($this->hasNext) {
$this->next = $this->oInnerIterator->current();
$this->nextKey = $this->oInnerIterator->key();
} else {
$this->next = null;
$this->nextKey = null;
}
}
}
}
public function rewind()
{
$this->hasPrevious = false;
$this->previous = null;
$this->previousKey = null;
$this->oInnerIterator->rewind();
$this->hasCurrent = $this->oInnerIterator->valid();
if ($this->hasCurrent) {
$this->current = $this->oInnerIterator->current();
$this->currentKey = $this->oInnerIterator->key();
$this->oInnerIterator->next();
$this->hasNext = $this->oInnerIterator->valid();
if ($this->hasNext) {
$this->next = $this->oInnerIterator->current();
$this->nextKey = $this->oInnerIterator->key();
} else {
$this->next = null;
$this->nextKey = null;
}
} else {
$this->current = null;
$this->currentKey = null;
$this->hasNext = false;
$this->next = null;
$this->nextKey = null;
}
}
public function valid()
{
return $this->hasCurrent;
}
public function hasNext()
{
return $this->hasNext;
}
public function getNext()
{
return $this->next;
}
public function getNextKey()
{
return $this->nextKey;
}
public function hasPrevious()
{
return $this->hasPrevious;
}
public function getPrevious()
{
return $this->previous;
}
public function getPreviousKey()
{
return $this->previousKey;
}
}
header("Content-type: text/plain; charset=utf-8");
$arr = [
"a" => "alma",
"b" => "banan",
"c" => "cseresznye",
"d" => "dio",
"e" => "eper",
];
$oNeighborIterator = new NeighborIterator(new ArrayIterator($arr));
foreach ($oNeighborIterator as $key => $value) {
// you can get previous and next values:
if (!$oNeighborIterator->hasPrevious()) {
echo "{FIRST}\n";
}
echo $oNeighborIterator->getPreviousKey() . " => " . $oNeighborIterator->getPrevious() . " -----> ";
echo "[ " . $key . " => " . $value . " ] -----> ";
echo $oNeighborIterator->getNextKey() . " => " . $oNeighborIterator->getNext() . "\n";
if (!$oNeighborIterator->hasNext()) {
echo "{LAST}\n";
}
}
You could get the keys of the array before the foreach, then use a counter to check the next element, something like:
//$arr is the array you wish to cycle through
$keys = array_keys($arr);
$num_keys = count($keys);
$i = 1;
foreach ($arr as $a)
{
if ($i < $num_keys && $arr[$keys[$i]] == $a)
{
// we have a match
}
$i++;
}
This will work for both simple arrays, such as array(1,2,3), and keyed arrays such as array('first'=>1, 'second'=>2, 'thrid'=>3).
A foreach loop in php will iterate over a copy of the original array, making next() and prev() functions useless. If you have an associative array and need to fetch the next item, you could iterate over the array keys instead:
foreach (array_keys($items) as $index => $key) {
// first, get current item
$item = $items[$key];
// now get next item in array
$next = $items[array_keys($items)[$index + 1]];
}
Since the resulting array of keys has a continuous index itself, you can use that instead to access the original array.
Be aware that $next will be null for the last iteration, since there is no next item after the last. Accessing non existent array keys will throw a php notice. To avoid that, either:
Check for the last iteration before assigning values to $next
Check if the key with index + 1 exists with array_key_exists()
Using method 2 the complete foreach could look like this:
foreach (array_keys($items) as $index => $key) {
// first, get current item
$item = $items[$key];
// now get next item in array
$next = null;
if (array_key_exists($index + 1, array_keys($items))) {
$next = $items[array_keys($items)[$index + 1]];
}
}
$next_data = $data;
$prev_key = null;
$prev_value = null;
foreach($data as $key => $value)
{
array_shift($next_data);
$next_key = key($next_data);
$next_value = $next_data[$next_key] ?? null;
// Do something here...
$prev_key = $key;
$prev_value = $value;
}
or if the array is associative then you could use current() similar to Andrei Krasutski's solution and key()
$values = [];
array_push($values, ["XYZ"=>100]);
array_push($values, ["ABC"=>10]);
array_push($values, ["XYZ"=>130]);
array_push($values, ["DEF"=>4]);
array_push($values, ["XYZ"=>5]);
$count = count($values);
foreach ($values as $index => $currentValue) {
if ($index < $count - 1) {
$nextValue = $values[$index + 1];
echo key($currentValue) . "=" . current($currentValue) . " followed by " . key($nextValue) . "/" . current($nextValue) . "<br>\n";
} else {
echo key($currentValue) . "=" . current($currentValue);
}
}
See https://onlinephp.io/c/dc58d for a running example.
or if the array is using named pairs:
$values = [];
array_push($values, ["type"=>"XYZ", "value"=>100]);
array_push($values, ["type"=>"ABC", "value"=>10]);
array_push($values, ["type"=>"XYZ", "value"=>130]);
array_push($values, ["type"=>"DEF", "value"=>"Lorem"]);
array_push($values, ["type"=>"XYZ", "value"=>5]);
$count = count($values);
foreach ($values as $index => $currentValue) {
if ($index < $count - 1) {
$nextValue = $values[$index + 1];
echo $currentValue['type'] . "=" . $currentValue['value']
. " followed by " . $nextValue['type'] . "/" . $nextValue['value'] . "<br>\n";
} else {
echo $currentValue['type'] . "=" . $currentValue['value'];
}
}

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