how to find the last element in a foreach? - php

This is what I am trying, using SimpleHtmlDom library
foreach($html->find('div[class="blogcontent]') as $a) {
foreach($a->find('p') as $elm) {
echo $elm->href .$elm->plaintext. '<p>';
if($elm, -1) {
return;
}
}
}
I am trying to implement what their doc say:
> // Find lastest anchor, returns element object or null if not found
> (zero based) $ret = $html->find('a', -1);
But I get:
Parse error: syntax error, unexpected ','
I need to stop the loop and don't echo the last p that it finds

If you want to remove the last tag then rather than iterate over all of the data, fetch all values from find() and then remove the last one with array_pop()...
foreach($html->find('div[class="blogcontent"]') as $a) {
$pTags = array_pop($a->find('p'));
foreach( $pTags as $elm) {
echo $elm->href .$elm->plaintext. '<p>';
}
}
If you just want the last <p> tag then
$pTags = $a->find('p');
$lastTag = $pTags[count($pTags)-1];

Rather than trying to identify the last entry, it might be easier to display the <p> before each entry except for the first
foreach($a->find('p') as $key => $elm) {
if ($key > 0) {
echo '<p>';
}
echo $elm->href .$elm->plaintext;
}

Alternative 1:
You could try to get the last element in the "old way" which is to use count() to get the number of elements then with a counter compare if it is in the last element then if it's true you skipt the last element. This way you can do it:
$a=$html->find('div[class="blogcontent]';
$i = 0;
foreach($a as $as) {
$b=$as->find('p');
$total_items = count($b);
foreach($b as $elm) {
if ($i == $total_items - 1) {
return; // or you can use break function to see if it stops on the last element
}
echo $elm->href .$elm->plaintext. '<p>';
}
}
Alternative 2:
You could use end() to know if you are on the last element this way:
$a=$html->find('div[class="blogcontent]';
foreach($a as $as) {
$b=$as->find('p');
foreach($b as $elm) {
if ($elm === end($b)) {
return; // or you can use break function to see if it stops on the last element
}
echo $elm->href .$elm->plaintext. '<p>';
}
}

Related

Loop within loop exit [duplicate]

I have a foreach loop and an if statement. If a match is found i need to ultimately break out of the foreach.
foreach ($equipxml as $equip) {
$current_device = $equip->xpath("name");
if ($current_device[0] == $device) {
// Found a match in the file.
$nodeid = $equip->id;
<break out of if and foreach here>
}
}
if is not a loop structure, so you cannot "break out of it".
You can, however, break out of the foreach by simply calling break. In your example it has the desired effect:
$device = "wanted";
foreach($equipxml as $equip) {
$current_device = $equip->xpath("name");
if ( $current_device[0] == $device ) {
// found a match in the file
$nodeid = $equip->id;
// will leave the foreach loop immediately and also the if statement
break;
some_function(); // never reached!
}
another_function(); // not executed after match/break
}
Just for completeness for others who stumble upon this question looking for an answer..
break takes an optional argument, which defines how many loop structures it should break. Example:
foreach (['1','2','3'] as $a) {
echo "$a ";
foreach (['3','2','1'] as $b) {
echo "$b ";
if ($a == $b) {
break 2; // this will break both foreach loops
}
}
echo ". "; // never reached!
}
echo "!";
Resulting output:
1 3 2 1 !
foreach($equipxml as $equip) {
$current_device = $equip->xpath("name");
if ( $current_device[0] == $device ) {
// found a match in the file
$nodeid = $equip->id;
break;
}
}
Simply use break. That will do it.
A safer way to approach breaking a foreach or while loop in PHP is to nest an incrementing counter variable and if conditional inside of the original loop. This gives you tighter control than break; which can cause havoc elsewhere on a complicated page.
Example:
// Setup a counter
$ImageCounter = 0;
// Increment through repeater fields
while ( condition ):
$ImageCounter++;
// Only print the first while instance
if ($ImageCounter == 1) {
echo 'It worked just once';
}
// Close while statement
endwhile;
For those of you landing here but searching how to break out of a loop that contains an include statement use return instead of break or continue.
<?php
for ($i=0; $i < 100; $i++) {
if (i%2 == 0) {
include(do_this_for_even.php);
}
else {
include(do_this_for_odd.php);
}
}
?>
If you want to break when being inside do_this_for_even.php you need to use return. Using break or continue will return this error: Cannot break/continue 1 level. I found more details here

break out of if and foreach

I have a foreach loop and an if statement. If a match is found i need to ultimately break out of the foreach.
foreach ($equipxml as $equip) {
$current_device = $equip->xpath("name");
if ($current_device[0] == $device) {
// Found a match in the file.
$nodeid = $equip->id;
<break out of if and foreach here>
}
}
if is not a loop structure, so you cannot "break out of it".
You can, however, break out of the foreach by simply calling break. In your example it has the desired effect:
$device = "wanted";
foreach($equipxml as $equip) {
$current_device = $equip->xpath("name");
if ( $current_device[0] == $device ) {
// found a match in the file
$nodeid = $equip->id;
// will leave the foreach loop immediately and also the if statement
break;
some_function(); // never reached!
}
another_function(); // not executed after match/break
}
Just for completeness for others who stumble upon this question looking for an answer..
break takes an optional argument, which defines how many loop structures it should break. Example:
foreach (['1','2','3'] as $a) {
echo "$a ";
foreach (['3','2','1'] as $b) {
echo "$b ";
if ($a == $b) {
break 2; // this will break both foreach loops
}
}
echo ". "; // never reached!
}
echo "!";
Resulting output:
1 3 2 1 !
foreach($equipxml as $equip) {
$current_device = $equip->xpath("name");
if ( $current_device[0] == $device ) {
// found a match in the file
$nodeid = $equip->id;
break;
}
}
Simply use break. That will do it.
A safer way to approach breaking a foreach or while loop in PHP is to nest an incrementing counter variable and if conditional inside of the original loop. This gives you tighter control than break; which can cause havoc elsewhere on a complicated page.
Example:
// Setup a counter
$ImageCounter = 0;
// Increment through repeater fields
while ( condition ):
$ImageCounter++;
// Only print the first while instance
if ($ImageCounter == 1) {
echo 'It worked just once';
}
// Close while statement
endwhile;
For those of you landing here but searching how to break out of a loop that contains an include statement use return instead of break or continue.
<?php
for ($i=0; $i < 100; $i++) {
if (i%2 == 0) {
include(do_this_for_even.php);
}
else {
include(do_this_for_odd.php);
}
}
?>
If you want to break when being inside do_this_for_even.php you need to use return. Using break or continue will return this error: Cannot break/continue 1 level. I found more details here

PHP loads not wanted elements from a XML file

I wan't to load some data from my XML file using this function:
public function getElements()
{
$elements = array();
$element = $this->documentElement->getElementsByTagName('elements')->item(0);
// checks if it has any immunities
if( isset($element) )
{
// read all immunities
foreach( $element->getElementsByTagName('element') as $v)
{
$v = $v->attributes->item(0);
// checks if immunity is set
if($v->nodeValue > 0)
{
$elements[$v->nodeName] = $v->nodeValue;
}
}
}
return $elements;
}
I wan't to load that elements from my XML file:
<elements>
<element physicalPercent="10"/>
<element icePercent="10"/>
<element holyPercent="-10"/>
</elements>
I wan't to load only element node name and node value.
Got this code in my query loop:
$elements = $monster->getElements();
$elN = 0;
$elC = count($elements);
if(!empty($elements)) {
foreach($elements as $element => $value) {
$elN++;
$elements_string .= $element . ":".$value;
if($elC != $elN)
$elements_string .= ", ";
}
}
And finally - the output of $elements_string variable is wrong:
earthPercent:50, holyPercent:50, firePercent:15, energyPercent:5, physicalPercent:25, icePercent:30, deathPercent:30firePercent:20, earthPercent:75firePercent:20, earthPercent:75firePercent:20, earthPercent:75physicalPercent:70, holyPercent:20, deathPerce
It should rather return:
physicalPercent:10, icePercent:10, holyPercent:-10
Could you help me one more time?:)
Thank you in advance.
Well the XML-Parser doesn't magically know which elements you want to load and which you won't - you have to filter this by yourself. Then you have to decide where you want to filter your desired elements in the getElements-function you posted or in your "query loop" as you call it.
Should the getElements be some kind of general function which must return all elements? Then you should change that check if($v->nodeValue > 0) to something like if(!empty($v->nodeValue)) otherwise you wont get the "holyPercent" value since this is negative (and the old expression becomes false).
Then in your "query loop", just select your desired elements:
foreach($elements as $element => $value) {
if(in_array($element, array("physicalPercent", "icePercent", "holyPercent"))) {
$elN++;
$elements_string .= $element . ":".$value;
if($elC != $elN)
$elements_string .= ", ";
}
}
Just:
$xml = new SimpleXMLElement($xmlfile);
And then:
for($i=1;$i<Count($xml->elements);$i++)
echo $xml->elements[$i][0];
Didn't try if it works with [0], usually i use :
echo $xml->elements[$i]['attributename'];

How to skip the 1st key in an array loop?

I have the following code:
if ($_POST['submit'] == "Next") {
foreach($_POST['info'] as $key => $value) {
echo $value;
}
}
How do I get the foreach function to start from the 2nd key in the array?
For reasonably small arrays, use array_slice to create a second one:
foreach(array_slice($_POST['info'],1) as $key=>$value)
{
echo $value;
}
foreach(array_slice($_POST['info'], 1) as $key=>$value) {
echo $value;
}
Alternatively if you don't want to copy the array you could just do:
$isFirst = true;
foreach($_POST['info'] as $key=>$value) {
if ($isFirst) {
$isFirst = false;
continue;
}
echo $value;
}
Couldn't you just unset the array...
So if I had an array where I didn't want the first instance,
I could just:
unset($array[0]);
and that would remove the instance from the array.
If you were working with a normal array, I'd say to use something like
foreach (array_slice($ome_array, 1) as $k => $v {...
but, since you're looking at a user request, you don't have any real guarantees on the order in which the arguments might be returned - some browser/proxy might change its behavior or you might simply decide to modify your form in the future. Either way, it's in your best interest to ignore the ordering of the array and treat POST values as an unordered hash map, leaving you with two options :
copy the array and unset the key you want to ignore
loop through the whole array and continue when seeing the key you wish to ignore
in loop:
if ($key == 0) //or whatever
continue;
Alternative way is to use array pointers:
reset($_POST['info']); //set pointer to zero
while ($value=next($_POST['info']) //ponter+1, return value
{
echo key($_POST['info']).":".$value."\n";
}
If you're willing to throw the first element away, you can use array_shift(). However, this is slow on a huge array. A faster operation would be
reset($a);
unset(key($a));
On a array filled with 1000 elements the difference is quite minimal.
Test:
<?php
function slice($a)
{
foreach(array_slice($a, 1) as $key)
{
}
return true;
}
function skip($a)
{
$first = false;
foreach($a as $key)
{
if($first)
{
$first = false;
continue;
}
}
return true;
}
$array = array_fill(0, 1000, 'test');
$t1 = time() + microtime(true);
for ($i = 0; $i < 1000; $i++)
{
slice($array);
}
var_dump((time() + microtime(true)) - $t1);
echo '<hr />';
$t2 = time() + microtime(true);
for ($i = 0; $i < 1000; $i++)
{
skip($array);
}
var_dump((time() + microtime(true)) - $t2);
?>
Output:
float(0.23605012893677)
float(0.24102783203125)
Working Code From My Website For Skipping The First Result and Then Continue.
<?php
$counter = 0;
foreach ($categoriest as $category) { if ($counter++ == 0) continue; ?>
It is working on opencart also in tpl file do like this in case you need.
foreach($_POST['info'] as $key=>$value) {
if ($key == 0) { //or what ever the first key you're using is
continue;
} else {
echo $value;
}
}
if you structure your form differently
<input type='text' name='quiz[first]' value=""/>
<input type='text' name='quiz[second]' value=""/>
...then in your PHP
if( isset($_POST['quiz']) AND
is_array($_POST['quiz'])) {
//...and we'll skip $_POST['quiz']['first']
foreach($_POST['quiz'] as $key => $val){
if($key == "first") continue;
print $val;
}
}
...you can now just loop over that particular structure and access rest normally
How about something like this? Read off the first key and value using key() and current(), then array_shift() to dequeue the front element from the array (EDIT: Don't use array_shift(), it renumbers any numerical indices in the array, which you don't always want!).
<?php
$arr = array(
'one' => "ONE!!",
'two' => "TWO!!",
'three' => "TREE",
4 => "Fourth element",
99 => "We skipped a few here.."
) ;
$firstKey = key( $arr ) ;
$firstVal = current( $arr ) ;
echo( "OK, first values are $firstKey, $firstVal" ) ;
####array_shift( $arr ) ; #'dequeue' front element # BAD! renumbers!
unset( $arr[ $firstKey ] ) ; # BETTER!
echo( "Now for the rest of them" ) ;
foreach( $arr as $key=>$val )
{
echo( "$key => $val" ) ;
}
?>

Find the last element of an array while using a foreach loop in PHP

I am writing a SQL query creator using some parameters. In Java, it's very easy to detect the last element of an array from inside the for loop by just checking the current array position with the array length.
for(int i=0; i< arr.length;i++){
boolean isLastElem = i== (arr.length -1) ? true : false;
}
In PHP they have non-integer indexes to access arrays. So you must iterate over an array using a foreach loop. This becomes problematic when you need to take some decision (in my case to append or/and parameter while building query).
I am sure there must be some standard way of doing this.
How do you solve this in PHP?
It sounds like you want something like this:
$numItems = count($arr);
$i = 0;
foreach($arr as $key=>$value) {
if(++$i === $numItems) {
echo "last index!";
}
}
That being said, you don't -have- to iterate over an "array" using foreach in php.
You could get the value of the last key of the array using end(array_keys($array)) and compare it to the current key:
$last_key = end(array_keys($array));
foreach ($array as $key => $value) {
if ($key == $last_key) {
// last element
} else {
// not last element
}
}
Note: This doesn't work because calling next() advances the array pointer, so you're skipping every other element in the loop
why so complicated?
foreach($input as $key => $value) {
$ret .= "$value";
if (next($input)==true) $ret .= ",";
}
This will add a , behind every value except the last one!
When toEnd reaches 0 it means it is at the last iteration of the loop.
$toEnd = count($arr);
foreach($arr as $key=>$value) {
if (0 === --$toEnd) {
echo "last index! $value";
}
}
The last value is still available after the loop, so if you just want to use it for more stuff after the loop this is better:
foreach($arr as $key=>$value) {
//something
}
echo "last index! $key => $value";
If you do not want to treat the last value as special inside loops. This should be faster if you have large arrays. (If you reuse the array after the loop inside the same scope you have to "copy" the array first).
//If you use this in a large global code without namespaces or functions then you can copy the array like this:
//$array = $originalArrayName; //uncomment to copy an array you may use after this loop
//end($array); $lastKey = key($array); //uncomment if you use the keys
$lastValue = array_pop($array);
//do something special with the last value here before you process all the others?
echo "Last is $lastValue", "\n";
foreach ($array as $key => $value) {
//do something with all values before the last value
echo "All except last value: $value", "\n";
}
//do something special with the last value here after you process all the others?
echo "Last is $lastValue", "\n";
And to answer your original question "in my case to append or/and parameter while building query"; this will loop over all the values, then join them together to a string with " and " between them but not before the first value or after the last value:
$params = [];
foreach ($array as $value) {
$params[] = doSomething($value);
}
$parameters = implode(" and ", $params);
There are already many answers, but it's worth to look into iterators as well, especially as it has been asked for a standard way:
$arr = range(1, 3);
$it = new CachingIterator(new ArrayIterator($arr));
foreach($it as $key => $value)
{
if (!$it->hasNext()) echo 'Last:';
echo $value, "\n";
}
You might find something that does work more flexible for other cases, too.
One way could be to detect if the iterator has next. If there is no next attached to the iterator it means you are in the last loop.
foreach ($some_array as $element) {
if(!next($some_array)) {
// This is the last $element
}
}
SINCE PHP 7.3 :
You could get the value of the last key of the array using array_key_last($array) and compare it to the current key:
$last_key = array_key_last($array);
foreach ($array as $key => $value) {
if ($key == $last_key) {
// last element
} else {
// not last element
}
}
to get first and last element from foreach array
foreach($array as $value) {
if ($value === reset($array)) {
echo 'FIRST ELEMENT!';
}
if ($value === end($array)) {
echo 'LAST ITEM!';
}
}
So, if your array has unique array values, then determining last iteration is trivial:
foreach($array as $element) {
if ($element === end($array))
echo 'LAST ELEMENT!';
}
As you see, this works if last element is appearing just once in array, otherwise you get a false alarm. In it is not, you have to compare the keys (which are unique for sure).
foreach($array as $key => $element) {
end($array);
if ($key === key($array))
echo 'LAST ELEMENT!';
}
Also note the strict coparision operator, which is quite important in this case.
Don't add a comma after the last value:
The array:
$data = ['lorem', 'ipsum', 'dolor', 'sit', 'amet'];
The function:
$result = "";
foreach($data as $value) {
$resut .= (next($data)) ? "$value, " : $value;
}
The result:
print $result;
lorem, ipsum, dolor, sit, amet
You can still use that method with associative arrays:
$keys = array_keys($array);
for ($i = 0, $l = count($array); $i < $l; ++$i) {
$key = $array[$i];
$value = $array[$key];
$isLastItem = ($i == ($l - 1));
// do stuff
}
// or this way...
$i = 0;
$l = count($array);
foreach ($array as $key => $value) {
$isLastItem = ($i == ($l - 1));
// do stuff
++$i;
}
Assuming you have the array stored in a variable...
foreach($array as $key=>$value)
{
echo $value;
if($key != count($array)-1) { echo ", "; }
}
If you need to do something for every element except either the first or the last and only if there is more than one element in the array, I prefer the following solution.
I know there are many solutions above and posted months/one year before mine, but this is something I feel is fairly elegant in its own right. The check every loop is also a boolean check as opposed to a numeric "i=(count-1)" check, which may allow for less overhead.
The structure of the loop may feel awkward, but you can compare it to the ordering of thead (beginning), tfoot (end), tbody (current) in HTML table tags.
$first = true;
foreach($array as $key => $value) {
if ($first) {
$first = false;
// Do what you want to do before the first element
echo "List of key, value pairs:\n";
} else {
// Do what you want to do at the end of every element
// except the last, assuming the list has more than one element
echo "\n";
}
// Do what you want to do for the current element
echo $key . ' => ' . $value;
}
For instance, in web development terms, if you want to add a border-bottom to every element except the last in an unordered list (ul), then you can instead add a border-top to every element except the first (the CSS :first-child, supported by IE7+ and Firefox/Webkit supports this logic, whereas :last-child is not supported by IE7).
You can feel free to reuse the $first variable for each and every nested loop as well and things will work just fine since every loop makes $first false during the first process of the first iteration (so breaks/exceptions won't cause issues).
$first = true;
foreach($array as $key => $subArray) {
if ($first) {
$string = "List of key => value array pairs:\n";
$first = false;
} else {
echo "\n";
}
$string .= $key . '=>(';
$first = true;
foreach($subArray as $key => $value) {
if ($first) {
$first = false;
} else {
$string .= ', ';
}
$string .= $key . '=>' . $value;
}
$string .= ')';
}
echo $string;
Example output:
List of key => value array pairs:
key1=>(v1_key1=>v1_val1, v1_key2=>v1_val2)
key2=>(v2_key1=>v2_val1, v2_key2=>v2_val2, v2_key3=>v2_val3)
key3=>(v3_key1=>v3_val1)
This should be the easy way to find the last element:
foreach ( $array as $key => $a ) {
if ( end( array_keys( $array ) ) == $key ) {
echo "Last element";
} else {
echo "Just another element";
}
}
Reference : Link
I have a strong feeling that at the root of this "XY problem" the OP wanted just implode() function.
As your intention of finding the EOF array is just for the glue. Get introduced to the below tactic. You need not require the EOF:
$given_array = array('column1'=>'value1',
'column2'=>'value2',
'column3'=>'value3');
$glue = '';
foreach($given_array as $column_name=>$value){
$where .= " $glue $column_name = $value"; //appending the glue
$glue = 'AND';
}
echo $where;
o/p:
column1 = value1 AND column2 = value2 AND column3 = value3
How about using "end"?
http://php.net/manual/en/function.end.php
It sounds like you want something like this:
$array = array(
'First',
'Second',
'Third',
'Last'
);
foreach($array as $key => $value)
{
if(end($array) === $value)
{
echo "last index!" . $value;
}
}
$array = array("dog", "rabbit", "horse", "rat", "cat");
foreach($array as $index => $animal) {
if ($index === array_key_first($array))
echo $animal; // output: dog
if ($index === array_key_last($array))
echo $animal; // output: cat
}
you can do a count().
for ($i=0;$i<count(arr);$i++){
$i == count(arr)-1 ? true : false;
}
or if you're looking for ONLY the last element, you can use end().
end(arr);
returns only the last element.
and, as it turns out, you CAN index php arrays by integers. It's perfectly happy with
arr[1];
You could also do something like this:
end( $elements );
$endKey = key($elements);
foreach ($elements as $key => $value)
{
if ($key == $endKey) // -- this is the last item
{
// do something
}
// more code
}
I kinda like the following as I feel it is fairly neat. Let's assume we're creating a string with separators between all the elements: e.g. a,b,c
$first = true;
foreach ( $items as $item ) {
$str = ($first)?$first=false:", ".$item;
}
Here's my solution:
Simply get the count of your array, minus 1 (since they start in 0).
$lastkey = count($array) - 1;
foreach($array as $k=>$a){
if($k==$lastkey){
/*do something*/
}
}
foreach ($array as $key => $value) {
$class = ( $key !== count( $array ) -1 ) ? " class='not-last'" : " class='last'";
echo "<div{$class}>";
echo "$value['the_title']";
echo "</div>";
}
Reference
If it is a single dimensional array you can do this to keep it short and sweet:
foreach($items as $idx => $item) {
if (!isset($items[$idx+1])) {
print "I am last";
}
}
Here's another way you could do it:
$arr = range(1, 10);
$end = end($arr);
reset($arr);
while( list($k, $v) = each($arr) )
{
if( $n == $end )
{
echo 'last!';
}
else
{
echo sprintf('%s ', $v);
}
}
If I understand you, then all you need is to reverse the array and get the last element by a pop command:
$rev_array = array_reverse($array);
echo array_pop($rev_array);
You could also try this to make your query... shown here with INSERT
<?php
$week=array('one'=>'monday','two'=>'tuesday','three'=>'wednesday','four'=>'thursday','five'=>'friday','six'=>'saturday','seven'=>'sunday');
$keys = array_keys($week);
$string = "INSERT INTO my_table ('";
$string .= implode("','", $keys);
$string .= "') VALUES ('";
$string .= implode("','", $week);
$string .= "');";
echo $string;
?>
For SQL query generating scripts, or anything that does a different action for the first or last elements, it is much faster (almost twice as fast) to avoid using unneccessary variable checks.
The current accepted solution uses a loop and a check within the loop that will be made every_single_iteration, the correct (fast) way to do this is the following :
$numItems = count($arr);
$i=0;
$firstitem=$arr[0];
$i++;
while($i<$numItems-1){
$some_item=$arr[$i];
$i++;
}
$last_item=$arr[$i];
$i++;
A little homemade benchmark showed the following:
test1: 100000 runs of model morg
time: 1869.3430423737 milliseconds
test2: 100000 runs of model if last
time: 3235.6359958649 milliseconds
Another way to go is to remember the previous loop cycle result and use that as the end result:
$result = $where = "";
foreach ($conditions as $col => $val) {
$result = $where .= $this->getAdapter()->quoteInto($col.' = ?', $val);
$where .= " AND ";
}
return $this->delete($result);

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