I am returning an array of values using mysql_fetch_array.
In the while loop, i need to perform an if condition on the next element of the array.
E.g
if next($row) == 'test'
{
...
}
The thing is 'next($row)' is returning me the index of the next element in the array. I would like to test for the next $row("name").
if next($row("name")) == 'test'
{
...
} //this code is incorrect
Is there a way of doing this in php?
Thanks a lot for your help :)
if the "next($row)" gives you the index of the next cell in the array then just use it to perform the test. $arr[next($row)] = the next cell value/obj/whatever you have there
foreach ($rows as $k => $row) {
if (isset($rows[$k+1]) && $rows[$k+1] == 'test') //do something
// Do normal stuff here
}
Related
I have an array as follows
$array[$id][$iterator][test1][test2][a][b][c][d]
I would like to test for each $iterator for the first instance of test1=not null (if so use a, b, c d)
else use the first instance of test2=not null use (a, b, c, d)
else use "---"
I don't know how to get a loop to break on first instance of a finding test1 and test2 or if there is a better construct to use than a loop in this case?
To break an iteration or loop
Just tell it to take a break :)
foreach ($array as $item) {
if ($item == 'I the great overlord command you to stop iterating!') {
break;
}
}
If you wanna...
if you just want to know if a certain value is in your array, you can do it like this:
if (in_array('The value you are looking for', $thatArrayItShouldBeIn)) {
die("Its in! Its in! Yippie!");
}
From the comments
Tell me if I'm wrong, but from your comment I come to understand you want your iteration to break at a certain loop?
foreach ($array as $key => $item) {
// Keys start at 0, so the first item is 0
if ($key == 3) {
// We'll stop looping at the 4th iteration
break;
}
}
Taking yet another look
If you really have an array with alot of layers and you just want to check one value for each iteration you can just do:
foreach ($array[$id]['iterator'] as $item) {
if ($item['test1'] == true) {
// Do something
}
} }
This question has been asked a thousand times, but each question I find talks about associative arrays where one can delete (unset) an item by using they key as an identifier. But how do you do this if you have a simple array, and no key-value pairs?
Input code
$bananas = array('big_banana', 'small_banana', 'ripe_banana', 'yellow_banana', 'green_banana', 'brown_banana', 'peeled_banana');
foreach ($bananas as $banana) {
// do stuff
// remove current item
}
In Perl I would work with for and indices instead, but I am not sure that's the (safest?) way to go - even though from what I hear PHP is less strict in these things.
Note that after foreach has run, I expected var_dump($bananas) to return an empty array (or null, but preferably an empty array).
1st method (delete by value comparison):
$bananas = array('big_banana', 'small_banana', 'ripe_banana', 'yellow_banana', 'green_banana', 'brown_banana', 'peeled_banana');
foreach ($bananas as $key=>$banana) {
if($banana=='big_banana')
unset($bananas[$key]);
}
2nd method (delete by key):
$bananas = array('big_banana', 'small_banana', 'ripe_banana', 'yellow_banana', 'green_banana', 'brown_banana', 'peeled_banana');
unset($bananas[0]); //removes the first value
unset($bananas[count($bananas)-1]); //removes the last value
//unset($bananas[n-1]); removes the nth value
Finally if you want to reset the keys after deletion process:
$bananas = array_map('array_values', $bananas);
If you want to empty the array completely:
unset($bananas);
$bananas= array();
it still has the indexes
foreach ($bananas as $key => $banana) {
// do stuff
unset($bananas[$key]);
}
for($i=0; $i<count($bananas); $i++)
{
//doStuff
unset($bananas[$i]);
}
This will delete every element after its use so you will eventually end up with an empty array.
If for some reason you need to reindex after deleting you can use array_values
How about a while loop with array_shift?
while (($item = array_shift($bananas)) !== null)
{
//
}
Your Note: Note that after foreach has run, I expected var_dump($bananas) to return an empty array (or null, but preferably
an empty array).
Simply use unset.
foreach ($bananas as $banana) {
// do stuff
// remove current item
unset($bananas[$key]);
}
print_r($bananas);
Result
Array
(
)
This question is old but I will post my idea using array_slice for new visitors.
while(!empty($bananas)) {
// ... do something with $bananas[0] like
echo $bananas[0].'<br>';
$bananas = array_slice($bananas, 1);
}
I have a PHP array created by the mysqli_fetch_array() function. The array holds several rows, and without looping through them, can I grab each row one by one?
I have tried:
$links= mysqli_fetch_array($links_result);
echo $links['link'][0];
But I can't seem to get it to work. What could I be doing wrong? Is this possible?
when you do
$links= mysqli_fetch_array($links_result);
you get the next row in result set in $links just access them by the column names.
you can loop over the results like
if(mysqli_num_rows($links_result)) {
while($links= mysqli_fetch_array($links_result)) {
//each row in here
var_dump($links);
}
}
If the field name is 'link'
Without looping:
echo $links[0]['link'];
where '0' is your row number
so, for row #505 it will be:
echo $links[505]['link'];
Just make sure it exists ;)
Without loop you can grab each row of array using recursive function
like this:
function printarray_withoutloop($userarray,$elementindex)
{
if(count($userarray) > $elementindex + 1)
{
echo $userarray[$elementindex]['link'];
printarray_withoutloop($userarray,$elementindex + 1)
}
elseif(count($userarray) == $elementindex + 1)
{
echo $userarray[$elementindex]['link'];
}
}
$links= mysqli_fetch_array($links_result);
$elementindex=0;
printarray_withoutloop($links,$elementindex);
I have created an array list with the following code:
<?php
$ids = array();
if (mysql_num_rows($query1))
{
while ($result = mysql_fetch_assoc($query1))
{
$ids["{$result['user_id']}"] = $result;
}
}
mysql_free_result($query1);
?>
Now, i need to read two elements from the array. The first is the current and the second one is the next element of array. So, the simplified process is the following:
i=0: current_element (pos:0), next_element (pos:1)
i=1: current_element (pos:1), next_element (pos:2)
etc
To do this, i have already written the following code, but i cant get the next element for each loop!
Here is the code:
if (count($ids))
{
foreach ($ids AS $id => $data)
{
$userA=$data['user_id'];
$userB=next($data['user_id']);
}
}
The message i receive is: Warning: next() expects parameter 1 to be array, string given in array.php on line X
Does anyone can help? Maybe i try to do it wrongly.
The current, next, prev, end functions work with the array itself and place a position mark on the array. If you want to use the next function, perhaps this is the code:
if (is_array($ids))
{
while(next($ids) !== FALSE) // make sure you still got a next element
{
prev($ids); // move flag back because invoking 'next()' above moved the flag forward
$userA = current($ids); // store the current element
next($ids); // move flag to next element
$userB = current($ids); // store the current element
echo(' userA='.$userA['user_id']);
echo('; userB='.$userB['user_id']);
echo("<br/>");
}
}
You'll get this text on the screen:
userA=1; userB=2
userA=2; userB=3
userA=3; userB=4
userA=4; userB=5
userA=5; userB=6
userA=6; userB=7
userA=7; userB=8
You get the first item, then loop over the rest and at the end of each loop you move the current item as the next first item ... the code should explain it better:
if (false !== ($userA = current($ids))) {
while (false !== ($userB = next($ids))) {
// do stuff with $userA['user_id'] and $userB['user_id']
$userA = $userB;
}
}
Previous answer
You can chunk the arrays into pairs:
foreach (array_chunk($ids, 2) as $pair) {
$userA = $pair[0]['user_id']
$userB = $pair[1]['user_id']; // may not exist if $ids size is uneven
}
See also: array_chunk()
I want to loop through an array with foreach to check if a value exists. If the value does exist, I want to delete the element which contains it.
I have the following code:
foreach($display_related_tags as $tag_name) {
if($tag_name == $found_tag['name']) {
// Delete element
}
}
I don't know how to delete the element once the value is found. How do I delete it?
I have to use foreach for this problem. There are probably alternatives to foreach, and you are welcome to share them.
If you also get the key, you can delete that item like this:
foreach ($display_related_tags as $key => $tag_name) {
if($tag_name == $found_tag['name']) {
unset($display_related_tags[$key]);
}
}
A better solution is to use the array_filter function:
$display_related_tags =
array_filter($display_related_tags, function($e) use($found_tag){
return $e != $found_tag['name'];
});
As the php documentation reads:
As foreach relies on the internal array pointer in PHP 5, changing it within the loop may lead to unexpected behavior.
In PHP 7, foreach does not use the internal array pointer.
foreach($display_related_tags as $key => $tag_name)
{
if($tag_name == $found_tag['name'])
unset($display_related_tags[$key];
}
Instead of doing foreach() loop on the array, it would be faster to use array_search() to find the proper key. On small arrays, I would go with foreach for better readibility, but for bigger arrays, or often executed code, this should be a bit more optimal:
$result=array_search($unwantedValue,$array,true);
if($result !== false) {
unset($array[$result]);
}
The strict comparsion operator !== is needed, because array_search() can return 0 as the index of the $unwantedValue.
Also, the above example will remove just the first value $unwantedValue, if the $unwantedValue can occur more then once in the $array, You should use array_keys(), to find all of them:
$result=array_keys($array,$unwantedValue,true)
foreach($result as $key) {
unset($array[$key]);
}
Check http://php.net/manual/en/function.array-search.php for more information.
if you have scenario in which you have to remove more then one values from the foreach array in this case you have to pass value by reference in for each:
I try to explain this scenario:
foreach ($manSkuQty as $man_sku => &$man_qty) {
foreach ($manufacturerSkus as $key1 => $val1) {
// some processing here and unset first loops entries
// here dont include again for next iterations
if(some condition)
unset($manSkuQty[$key1]);
}
}
}
in second loop you want to unset first loops entries dont come again in the iteration for performance purpose or else then unset from memory as well because in memory they present and will come in iterations.
There are already answers which are giving light on how to unset. Rather than repeating code in all your classes make function like below and use it in code whenever required. In business logic, sometimes you don't want to expose some properties. Please see below one liner call to remove
public static function removeKeysFromAssociativeArray($associativeArray, $keysToUnset)
{
if (empty($associativeArray) || empty($keysToUnset))
return array();
foreach ($associativeArray as $key => $arr) {
if (!is_array($arr)) {
continue;
}
foreach ($keysToUnset as $keyToUnset) {
if (array_key_exists($keyToUnset, $arr)) {
unset($arr[$keyToUnset]);
}
}
$associativeArray[$key] = $arr;
}
return $associativeArray;
}
Call like:
removeKeysFromAssociativeArray($arrValues, $keysToRemove);