Geek Answers Handbook

Extend elements from next foreach element in PHP?

I use the background style warning system "PHP" for my website, which basically says "if there is an X percent change between the current array entry and the next, print an error."

So, I iterate over the elements of the array in the foreach loop, but should be able to do something like this: (note: this is just a basic example, but this should be enough to get the idea)

foreach($array as $a)
{
$thisValue = $a['value'];
$nextValue = next($a['value']);

$percentageDiff = ($nextValue-$thisValue)/$thisValue;
}

I added next () tags to get the next value, but I understand that this only works for arrays. Is there anything else I can use to get the next foreach element?

Thank you for your time!

+5
8

-, .

$prev = null;
foreach ($item as $i){
    if ($prev !== null){
        diff($prev, $i);
    }
    $prev = $i
}
+10

: foreach. for:

for ($i = 0; $i < count($array); $i++) {
    if (isset($array[$i + 1])) {
        $thisValue = $array[$i]['value'];
        $nextValue = $array[$i + 1]['value'];

        $percentageDiff = ($nextValue-$thisValue)/$thisValue;
    }
}
+4

:

foreach($array as $a)
{
    $array_copy = $array;
    $thisValue = $a['value'];

    $nextValue = next($array_copy);
    $nextValue = $nextValue['value'];

    $percentageDiff = ($nextValue-$thisValue)/$thisValue;
}

, 1.

+1

IMO - . . , .

, foreach C-, for - , : PHP , array_values() .

+1

foreach, , :

$previous = null;
foreach ($array as $a) {
    if (!is_null($previous)) {
        $thisValue = $previous['value'];
        $nextValue = $a['value'];
        $percentageDiff = ($nextValue-$thisValue)/$thisValue;
    }
    $previous = $a;
}

.

+1

for, foreach?

<?php
    $testArray = array(10,20,30,40,50,60,70,80,90,100);

    $elementCount = count($testArray);
    for($loop=0; $loop<$elementCount; $loop++) {

        $thisValue = $testArray[$loop];

        // Check if there *is* a next element.
        $nextValue = $loop + 1 < $elementCount ? $testArray[$loop + 1] : null;

        // Calculate the percentage difference if we have a next value.
        if($nextValue) $percentageDiff = ($nextValue-$thisValue)/$thisValue;
    }
?>
+1

' , :

$lastValue = NULL;
foreach ($array as $a) {
    if ($lastValue === NULL) {
        $lastValue = $a['value'];
        continue;
    }

    $percentageDiff = ($a['value'] - $lastValue) / $lastValue;

    $lastValue = $a['value'];
}
+1
for($i=0;$i<count($array);$i++) {
$thisValue = $array[$i];
$nextValue = $array[i+1]; // will not be set if $i==count($array)-1
$percentageDiff = ($nextValue-$thisValue)/$thisValue;
}

, , , next()/prev() .. ,

foreach, foreach .

, :

$arrayobject = new ArrayObject($array);
$iterator = $arrayobject->getIterator();

        for($i=0;$i<count($array);$i++) {
           $iterator->seek($i);
           $thisValue = $iterator->current();
           $iterator->seek($i+1);
           $nextValue = $iterator->current(); 
           $percentageDiff = ($nextValue-$thisValue)/$thisValue;
        }
+1

More articles:


All Articles