natsort
regarding references with foreach, you can use them directly. Obviating various posts which provide many lines of 'work arounds'.
$array = array(1,2,3,4,5);
foreach($array as &$value)
or use $key
foreach($array as $key => $value)
{
$array[$key] = '...';
}
next
(PHP 4, PHP 5, PECL axis2:0.1.0-0.1.1 xmlreader:1.0-1.0.1)
next — Advance the internal array pointer of an array
Descrierea
next() behaves like current(), with one difference. It advances the internal array pointer one place forward before returning the element value. That means it returns the next array value and advances the internal array pointer by one.
Valorile întroarse
Returns the array value in the next place that's pointed to by the internal array pointer, or FALSE if there are no more elements.
Avertizare
Această funcţie poate întoarce valoarea Boolean FALSE, dar poate de asemenea întoarce o valoare non-Boolean care evaluează în FALSE, cum ar fi 0 sau "". Vă rugăm să citiţi secţiunea despre tipul Boolean pentru mai multe informaţii. Utilizaţi operatorul === pentru a verifica valoarea întoarsă de această funcţie.
Exemple
Example #1 Example use of next() and friends
<?php
$transport = array('foot', 'bike', 'car', 'plane');
$mode = current($transport); // $mode = 'foot';
$mode = next($transport); // $mode = 'bike';
$mode = next($transport); // $mode = 'car';
$mode = prev($transport); // $mode = 'bike';
$mode = end($transport); // $mode = 'plane';
?>
add a note
User Contributed Notesnext
ThinkMedical at Gmail dot com
03-Sep-2008 12:27
03-Sep-2008 12:27
rayro at gmx dot de
28-Jun-2008 03:23
28-Jun-2008 03:23
@GPatmore and @gigs at gigstaggart dot com:
foreach() does not use the real array you are give in...
If you want to delete something in the array, the array passed through foreach() has to be a reference to your array...
<?php
$my_array = explode(',','a,b,c,d,e,f,g');
$ary =& $my_array;
// Note: foreach(&ary => $a) wont work! Thats a little bit pity... :(
foreach($ary as $a){
print 'letter ' . $a;
if(next($ary)){
unset($ary[count($ary) - 1]);
print '<br>';
}else{
print '<br>dun!';
}
}
?>
would finally print:
letter a
letter b
letter c
letter d
dun!
Ohterwise you are able to make a while() as followed:
<?php
$ary = explode(',','a,b,c,d,e,f,g');
while(list($k,$a) = each($ary)) {
print 'letter ' . $a;
if(next($ary)){
prev($ary);
unset($ary[count($ary) - 1]);
print '<br>';
}else{
print '<br>dun!';
}
}
?>
Consider the prev() after the next()... ;)
This is essential for the each(), which means that YOU decide the pointer, while foreach() uses own pointers...
adityabhai [at] gmail com [Aditya Bhatt]
09-May-2008 02:14
09-May-2008 02:14
<?php
class Steps {
private $all;
private $count;
private $curr;
public function __construct () {
$this->count = 0;
}
public function add ($step) {
$this->count++;
$this->all[$this->count] = $step;
}
public function setCurrent ($step) {
reset($this->all);
for ($i=1; $i<=$this->count; $i++) {
if ($this->all[$i]==$step) break;
next($this->all);
}
$this->curr = current($this->all);
}
public function getCurrent () {
return $this->curr;
}
public function getNext () {
self::setCurrent($this->curr);
return next($this->all);
}
public function getPrev () {
self::setCurrent($this->curr);
return prev($this->all);
}
}
?>
Demo Example:
<?php
$steps = new Steps();
$steps->add('1');
$steps->add('2');
$steps->add('3');
$steps->add('4');
$steps->add('5');
$steps->add('6');
$steps->setCurrent('4');
echo $steps->getCurrent()."<br />";
echo $steps->getNext()."<br />";
echo $steps->getPrev()."<br />";
$steps->setCurrent('2');
echo $steps->getCurrent()."<br />";
echo $steps->getNext()."<br />";
echo $steps->getPrev()."<br />";
?>
darkside at i dot ua
11-Dec-2007 12:36
11-Dec-2007 12:36
This class implements simple operations with array
<?php
class Steps {
private $all;
private $count;
private $curr;
public function __construct () {
$this->count = 0;
}
public function add ($step) {
$this->count++;
$this->all[$this->count] = $step;
}
public function setCurrent ($step) {
reset($this->all);
for ($i=1; $i<=$this->count; $i++) {
if ($this->all[$i]==$step) break;
next($this->all);
}
$this->curr = current($this->all);
}
public function getCurrent () {
return $this->curr;
}
public function getNext () {
self::setCurrent($this->curr);
return next($this->all);
}
}
?>
usage example:
<?php
$steps = new Steps();
$steps->add('one');
$steps->add('two');
$steps->add('three');
$steps->setCurrent('one');
echo $steps->getCurrent()."<br />";
echo $steps->getNext()."<br />";
$steps->setCurrent('two');
echo $steps->getCurrent()."<br />";
echo $steps->getNext()."<br />";
?>
gigs at gigstaggart dot com
22-Nov-2007 03:22
22-Nov-2007 03:22
To GPatmore, I wrote a function almost just like yours to skip the last element when outputting something like CSV...
It doesn't always work... I would think it wouldn't work at all and would cause the loop to skip every other element, but it doesn't.
next() inside foreach instead returns false on some elements that may not be the last one... I don't know the cause yet. But don't do that. It's not safe. :)
gg2005 at gmail dot com
06-Feb-2007 10:32
06-Feb-2007 10:32
Don't confuse next with continue!
If you're a Perl developer starting with PHP, you might try to use "next" inside a loop to skip to the next iteration...
i.e.,
foreach ($things as $thing) {
if (something I don't like about $thing) {
next;
}
blah....
}
The php compiler will take next... but it's not going to work.
Do this instead:
foreach ($things as $thing) {
if (something I don't like about $thing) {
continue;
}
blah....
}
GPatmore
12-Oct-2006 09:14
12-Oct-2006 09:14
If your using a foreach loop, unless you for a reference, PHP will make a copy of the array to use it the loop.
So, when I need to take a different action for the last element in the array I use the following:
<?php
$ary = explode(',','a,b,c,d,e,f,g');
foreach($ary as $a){
print 'letter ' . $a;
if(next($ary)){
print '<br>';
}else{
print '<br>dun!';
}
}
?>
Output:
letter a
letter b
letter c
letter d
letter e
letter f
letter g
dun!
NOTE::
PHP5 has added an ability to reference the variable in a foreach like:
<?php
foreach($ary as &$a){}
?>
this will probably cause undesired results when using the method above.
also if the array is changed in any way as to cause the length of the original array to become different then the copy, it will not work.
Consider the following example:
<?php
$ary = explode(',','a,b,c,d,e,f,g');
foreach($ary as $a){
print 'letter ' . $a;
if(next($ary)){
unset($ary[count($ary) - 1]);
print '<br>';
}else{
print '<br>dun!';
}
}
?>
output:
letter a
letter b
letter c
letter d
dun!letter e
dun!letter f
dun!letter g
dun!
tom at nono dot be
27-Jul-2006 01:19
27-Jul-2006 01:19
I see some questions like "how can I know if an array has a next value without changing its internal pointer" and some pretty complicated responses that DO work mind you and in some cases you'll need them...
But suppose you just need a different action within a foreach loop when reaching the final item:
(it won't be usefull in every situation, but in most it will)
$numOfItems = count($someArray);
$counter = 0;
foreach ($someArray as $key => value){
$counter += 1;
if ($counter <> $numOfItems){
//here all next items exist
} else {
//final item
}
}
Sigmar
31-May-2006 12:02
31-May-2006 12:02
And if you want to know if there are any array elements in array before given key, you can use this function:
function any_array_keys_before($keyname, &$array) {
if (!is_array($array)) {
return false;
}
if (empty($keyname)) {
return false;
}
$set = false;
$count = 0;
foreach ($array as $key => $value) {
if ($set === false && $key != $keyname) {
$count ++;
} else if ($key == $keyname) {
$set = true;
}
}
return $count > 0 ? true : false;
}
Sigmar
30-May-2006 11:52
30-May-2006 11:52
If you want to check, if there are some more elements in array after given key, you can use the following function:
function more_array_keys($keyname, &$array) {
if (!is_array($array)) {
return false;
}
if (empty($keyname)) {
return false;
}
$set = false;
$count = 0;
foreach ($array as $key => $value) {
if ($set === true) {
$count++;
}
if ($key == $keyname) {
$set = true;
}
}
return $count > 0 ? true : false;
}
tino at infeon dot com
13-May-2006 05:48
13-May-2006 05:48
this may be handy and i didnt know where else to post it.. i need a simple function to cycle through an array i eventually made it into a class so i could have multiple cycles.. if you like it or find it usefull please email me and let me know
class Cycle
{
var $position;
var $dataArray;
var $dataArrayCount;
function Cycle()
{
$this->dataArray = func_get_args();
$this->dataArrayCount = count($this->dataArray);
}
function Display()
{
$this->position = (!isset($this->position) || $this->position >= ($this->dataArrayCount - 1)) ? 0 : $this->position += 1;
return $this->dataArray[$this->position];
}
}
$bgColor = new Cycle('#000000', '#FFFFFF', '#FF0000');
echo $bgcolor->Display();
//returns #000000
echo $bgcolor->Display();
//returns #FFFFFF
echo $bgcolor->Display();
//returns #FF0000
echo $bgcolor->Display();
//returns #000000
brentimus
28-Apr-2005 07:10
28-Apr-2005 07:10
Papipo's function below is usefull in concept but does not work.
"Since you do not pass the array by reference, its pointer is only moved inside the function."
This is true, but the array you are manipulating in your has_next() function will have it's pointer set to the first element, not the same position as the original array. What you want to do is pass the array to the has_next() function via reference. While in the has_next() function, make a copy of the array to work on. Find out the current pointer position of the original array and set the pointer on the working copy of the array to the same element. Then you may test to see if the array has a "next" element.
Try the followig insetad:
<?php
function has_next(&$array)
{
$A_work=$array; //$A_work is a copy of $array but with its internal pointer set to the first element.
$PTR=current($array);
array_set_pointer($A_work, $PTR);
if(is_array($A_work))
{
if(next($A_work)===false)
return false;
else
return true;
}
else
return false;
}
function array_set_pointer(&$array, $value)
{
reset($array);
while($val=current($array))
{
if($val==$value)
break;
next($array);
}
}
?>
papipo's gmail account
13-Oct-2004 10:47
13-Oct-2004 10:47
I need to know if an array has more items, but without moving array's internail pointer. Thats is, a has_next() function:
<?php
function has_next($array) {
if (is_array($array)) {
if (next($array) === false) {
return false;
} else {
return true;
}
} else {
return false;
}
}
$array = array('fruit', 'melon');
if (has_next($array)) {
echo next($array);
}
// prints 'melon'
?>
Since you do not pass the array by reference, its pointer is only moved inside the function.
Hope that helps.
lukasz at karapuda dot com
18-Aug-2004 07:06
18-Aug-2004 07:06
This function will return the previous,next neighbors of an array entry within an associative array. If the specified $key points to the last or first element of the array, the first or last keys of the array will be returned consecutively. This is an improved version of the same function posted earlier.
<?php
function array_neighbor($arr, $key)
{
$keys = array_keys($arr);
$keyIndexes = array_flip($keys);
$return = array();
if (isset($keys[$keyIndexes[$key]-1])) {
$return[] = $keys[$keyIndexes[$key]-1];
}
else {
$return[] = $keys[sizeof($keys)-1];
}
if (isset($keys[$keyIndexes[$key]+1])) {
$return[] = $keys[$keyIndexes[$key]+1];
}
else {
$return[] = $keys[0];
}
return $return;
}
?>
court shrock
21-May-2004 01:36
21-May-2004 01:36
This code returns neighbors of the specified key. The result will be empty if it doesn't have any neighbors. My approach was to use the order of keys to determine neighbors, which is differnet from just getting the next/previous element in an array. Feel free to point out stupidities :)
<?php
function array_neighbor($arr, $key)
{
krsort($arr);
$keys = array_keys($arr);
$keyIndexes = array_flip($keys);
$return = array();
if (isset($keys[$keyIndexes[$key]-1]))
$return[] = $keys[$keyIndexes[$key]-1];
if (isset($keys[$keyIndexes[$key]+1]))
$return[] = $keys[$keyIndexes[$key]+1];
return $return;
}
?>
bm at ANTISPAM dot solidwave dot com
17-Apr-2004 06:49
17-Apr-2004 06:49
Take care when replacing code using reset()/next() with code using foreach as foreach does not update the array's internal pointer. This means you cannot, say, use next() to skip an element in foreach loop, or use current() within a function to get a reference to the current element. You probably have code depending on this internal pointer and replacing it will be more work than you anticipated.
See http://www.php.net/foreach