{"id":1616,"date":"2017-03-22T13:31:06","date_gmt":"2017-03-22T08:01:06","guid":{"rendered":"https:\/\/www.wikitechy.com\/technology\/?p=1616"},"modified":"2017-03-29T09:58:48","modified_gmt":"2017-03-29T04:28:48","slug":"determine-first-last-iteration-foreach-loop","status":"publish","type":"post","link":"https:\/\/www.wikitechy.com\/technology\/determine-first-last-iteration-foreach-loop\/","title":{"rendered":"PHP – How to determine the first and last iteration in a for each loop"},"content":{"rendered":"

The question is simple. we have a for each loop in our code:<\/span><\/h4>\n
Php Code<\/span> <\/div> 
foreach($array as $element) {\/\/code}<\/code><\/pre> <\/div>\n
In this loop, we want to react differently when we are in first or last iteration.<\/p>\n
How to do this?<\/p>\n
Php loops for each<\/p>\n
Use a counter:<\/span><\/h4>\n
 
 Php Code<\/span> <\/div> 
$i = 0;$len = count($array);foreach ($array as $item) {    if ($i == 0) {        \/\/ first    } else if ($i == $len - 1) {        \/\/ last    }    \/\/ \u2026    $i++;}<\/code><\/pre> <\/div>\n
Another example:<\/span><\/h4>\n
 
 Php Code<\/span> <\/div> 
$arr = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);foreach ($arr as $a) {\/\/ This is the line that does the checkingif (!each($arr)) echo "End!\\n";echo $a."\\n";}<\/code><\/pre> <\/div>\n[ad type=”banner”]\n
Try this code:<\/span><\/h4>\n
 
 Php Code<\/span> <\/div> 
\/\/Store the last key$lastkey = key(end($array)); foreach($array as $key => $element) {    ....do array stuff    if ($lastkey === key($array))        echo 'LAST ELEMENT!';}<\/code><\/pre> <\/div>\n
If your array has unique array values, then determining the first and last element is trivial:<\/span><\/h4>\n
 
 Php Code<\/span> <\/div> 
foreach($array as $element) {    if ($element === reset($array))        echo 'FIRST ELEMENT!';    if ($element === end($array))        echo 'LAST ELEMENT!';}<\/code><\/pre> <\/div>\n
This works if last and first elements are appearing just once in an array, otherwise you get false positives. Therefore, you have to compare the keys (they are unique for sure).<\/p>\n
 
 Php Code<\/span> <\/div> 
foreach($array as $key => $element) {    reset($array);    if ($key === key($array))        echo 'FIRST ELEMENT!';    end($array);    if ($key === key($array))        echo 'LAST ELEMENT!';}<\/code><\/pre> <\/div>\n
Update: Some people are concerned about performance and\/or modifying the array pointer inside a foreach loop.<\/p>\n
For those, you can cache the key value before the loop.<\/p>\n
 
 Php Code<\/span> <\/div> 
reset($array);$first = key($array);foreach($array as $key => $element) {    if ($key === $first)        echo 'FIRST ELEMENT!';}<\/code><\/pre> <\/div>\n
A more simplified version of the above and presuming you’re not using custom indexes…<\/p>\n
 
 Php Code<\/span> <\/div> 
$len = count($array);foreach ($array as $index => $item) {    if ($index == 0) {        \/\/ first    } else if ($index == $len - 1) {        \/\/ last    }}<\/code><\/pre> <\/div>\n[ad type=”banner”]\n
If you only need just the first element then you may try this code.<\/p>\n
 
 Php Code<\/span> <\/div> 
$firstElement = true;foreach ($reportData->result() as $row) {       if($firstElement) { echo "first element"; $firstElement=false; }       \/\/ Other lines of codes here}<\/code><\/pre> <\/div>\n","protected":false},"excerpt":{"rendered":"
PROBLEM : The question is simple. we have a for each loop in our code: In this loop, we want to react differently when we are in first or last iteration. How to do this? Php loops for each SOLUTION 1: Use a counter: SOLUTION 2: Another example: [ad type=”banner”] SOLUTION 3: Try this code: […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[3319,3320,3321,1204,3318,3326,3323,3325,3322,3324],"class_list":["post-1616","post","type-post","status-publish","format-standard","hentry","category-php","tag-find-the-last-element-of-an-array-while-using-a-foreach-loop-in-php","tag-how-do-i-loop-through-or-enumerate-a-javascript-object","tag-how-do-you-remove-an-array-element-in-a-foreach-loop","tag-how-does-php-foreach-actually-work","tag-how-to-find-the-foreach-index","tag-how-to-make-last-uploaded-images-appear-first-in-foreach-loop","tag-iteration-problems-with-foreach-loop","tag-php-effective-way-to-determine-last-loop-in-foreach","tag-php-how-to-skip-last-element-in-foreach-loop","tag-while-loop-runs-only-in-the-first-iteration-of-foreach-loop"],"_links":{"self":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/1616","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/comments?post=1616"}],"version-history":[{"count":0,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/1616\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/media?parent=1616"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/categories?post=1616"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/tags?post=1616"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}