I want to make a method that returns keys and values. But only if the keys include the following string "_1" and "__last".
If only one matches then exit the function, only if the two string are included in the key, return the key with the value for a weather.
$infoList = array("_key_1"=>array("time"=>9, "day"=>"Tuesday", "weather"=>"sunny",
"humidity"=>"80%"),
"_key_2"=>array("time"=>5, "day"=>"Tuesday", "weather"=>"cloudy"),
"_key__last"=>array("time"=>3, "day"=>"Sunday", "weather"=>"rainy"))
public function getData() {
$list = array();
foreach($infoList as $key){
if(preg_match('/(_key)_(_1)/', $key) && preg_match('/(_key)_(__last)/', $key) == TRUE){
$list[$key] = $list[$key]["weather"]
}
}
return $list
}
You are making your life so much more difficult that it need be, use str_contains() its easier than building complex REGEX's and getting very confused by the look of it :)
I also fixed a number of other mistakes, such as the foreach that was not going to work, so check all the code.
It is also better to pass data to a function/method otherwise you get into scoping issues!
$infoList = array("_key_1"=>array("time"=>9, "day"=>"Tuesday", "weather"=>"sunny", "humidity"=>"80%"),
"_key_2"=>array("time"=>5, "day"=>"Tuesday", "weather"=>"cloudy"),
"_key__last"=>array("time"=>3, "day"=>"Sunday", "weather"=>"rainy"));
function getData(Array $infoList) {
$list = [];
$found = 0;
foreach($infoList as $key => $val) {
if( str_contains($key, '_1') || str_contains($key, '__last') ) {
$list[$key] = $val["weather"];
$found++;
}
}
if ( $found >= 2 ) {
return $list;
} else {
return false;
}
}
$res = getData($infoList);
if ( $res !== false ){
print_r($res);
} else {
echo 'Not Found';
}
RESULTS
Array
(
[_key_1] => sunny
[_key__last] => rainy
)
If you want to stick with RegEx, you can use positive lookaheads, the same way you check for passwords characters :
<?php
$pattern = '/^(?=.*_1)(?=.*_last).*$/';
$shouldMatch = [
'_1_last',
'foo_1bar_lasthello',
'_last_1',
'foo_lastbar_1hello'
];
echo 'next ones should match : ' . PHP_EOL;
foreach ($shouldMatch as $item)
{
if (preg_match($pattern, $item))
echo $item . PHP_EOL;
}
$shouldNOTMatch = [
'_2_first',
'bar_lasthello',
'foo_las_1hello'
];
echo 'next ones should NOT match : ' . PHP_EOL;
foreach ($shouldNOTMatch as $item)
{
// v------------ check
if (!preg_match($pattern, $item))
echo $item . PHP_EOL;
}
Output :
next ones should match :
_1_last
foo_1bar_lasthello
_last_1
foo_lastbar_1hello
next ones should NOT match :
_2_first
bar_lasthello
foo_las_1hello
I know that this is a similar question:
Updating a Multidimensional Array in PHP
but is different my problem:
I have a multidimensional array and I want to check if a value inside it is equal another, if tue update value.
I have tried in this way:
$room_id = '1205222__1763659__386572_1';
foreach($cart as $c){
if($c['item_type'] == 'hotel'){
foreach($c as $key => $value){
if(substr($key, 0, 7) == 'room_id'){
if($value == $room_id) {
$c[$key] = '';
}
}
}
}
}
This is an example of my array:
array() {
[0]=>
array() {
["item_type"]=> "hotel"
["room_id_0"]=> "1205222__1763659__386572_1"
["room_id_1"]=> "1205222__1763659__386572_2"
},
[1]=>
array() {
["item_type"]=> "hotel"
["room_id_0"]=> "1205222__1763659__386572_3"
["room_id_1"]=> "1205222__1763659__386572_4"
}
}
I have checked if the conditions work right and yes, but when I make the assignment and after print the array again the array isn't changed.
Can someone help me?
Thanks
this won't work as you are changing $c which is a copy of the array $cart. you would need to get the array key of the first array value and the array key of the second array and then update:
try this
foreach($cart as $a => $c){
if($c['item_type'] == 'hotel'){
foreach($c as $key => $value){
if(substr($key, 0, 7) == 'room_id'){
if($value == $room_id) {
$cart[$a][$key] = '';
}
}
}
}
}
You can call foreach with passing $c by reference, like this:
foreach($cart as &$c){
...
This should let you change the value of the item.
To take it a step further, you could also pass $value by reference, and then change its value by modifying $value:
// Notice &$c
foreach($cart as &$c){
if($c['item_type'] == 'hotel'){
// Notice &$value
foreach($c as $key => &$value){
if(substr($key, 0, 7) == 'room_id'){
if($value == $room_id) {
// Instead of $c[$key]
$value = '';
}
}
}
}
}
I have a question about arrays and foreach.
If i have an array like this:
$test_arr = array();
$test_arr['name1'] = "an example sentence";
$test_arr['anything'] = "dsfasfasgsdfg";
$test_arr['code'] = "4334refwewe";
$test_arr['empty1'] = "";
$test_arr['3242'] = "";
how can I do a foreach and "pick" only the ones that have values? (in my array example, would only take the first 3 ones, name1, anything and code).
I tried with
foreach ($test_arr as $test) {
if (strlen($test >= 1)) {
echo $test . "<br>";
}
}
but it doesn't work. Without the "if" condition it works, but empty array values are taken into consideration and I don't want that (because I need to do a <br> after each value and I don't want a <br> if there is no value)
Sorry if I don't explain myself very well, I hope you understand my point. Shouldn't be too difficult I guess..
Thanks for your help !
Maybe will work
foreach ($test_arr as $test) {
if (strlen($test)!=="") {
echo $test . "<br>";
}
}
Your solution with corrected syntax:
foreach ($test_arr as $test) {
if (strlen($test)>=1) {
echo $test . "<br>";
}
}
Since empty strings are false, you could just do this (but you'd exclude 0's with the if):
foreach ($test_arr as $key => $val) {
if ($val) {
echo $val. "<br>";
}
}
If it has to be an empty string then (excluding 0 and FALSE):
foreach ($test_arr as $key => $val) {
// the extra = means that this will only return true for strings.
if ($val !== '' ) {
echo $val. "<br>";
}
}
Since it looks like you're using an associative array, you should be able to do this:
foreach( $test_arr as $key => $value )
{
if( $value != "" )
{
echo $value . "<br />";
}
}
As shown, you can test $value for an empty string directly. Since this is precisely the test you are trying to accomplish, I would hope that this would solve your problem perfectly.
On another note, this is pretty straight forward and should be very maintainable in the future when you've forgotten exactly what it was that you were doing!
You are better off to use a while loop like this:
while(list($test_key, $test_value) = each($test_arr))
{
if($test_value != "") { echo $test_value . "<br/>"; }
}
reset($test_arr);
If your array gets large, the while will be much faster. Even on small arrays, I have noticed a big difference in the execution time.
And if you really don't want the array key. You can just do this:
while(list(, $test_value) = each($test_arr))
{
if($test_value != "") { echo $test_value . "<br/>"; }
}
reset($test_arr);
You can check if the value is emtpy with empty().
Note that values like 0 or false are considered empty as well, so you might have to check for string length instead.
just a simple typing error:
foreach ($test_arr as $test) {
if (strlen($test) >= 1) {
echo $test . "<br>";
}
}
Try this:
foreach ($test_arr as $test) {
if (strlen($test) > 0) {
echo $test . "<br>";
}
}
Wondering what would be a good method to get the first iteration on a foreach loop.
I want to do something different on the first iteration.
Is a conditional our best option on these cases?
Yes, if you are not able to go through the object in a different way (a normal for loop), just use a conditional in this case:
$first = true;
foreach ( $obj as $value )
{
if ( $first )
{
// do something
$first = false;
}
else
{
// do something
}
// do something
}
Even morer eleganterer:
foreach($array as $index => $value) {
if ($index == 0) {
echo $array[$index];
}
}
That example only works if you use PHP's built-in array append features/function or manually specify keys in proper numerical order.
Here's an approach that is not like the others listed here that should work via the natural order of any PHP array.
$first = array_shift($array);
//do stuff with $first
foreach($array as $elem) {
//do stuff with rest of array elements
}
array_unshift($array, $first); //return first element to top
You can simply add a counter to the start, like so:
$i = 0;
foreach($arr as $a){
if($i == 0) {
//do ze business
}
//the rest
$i++;
}
I saw this solution on a blog post in my search result set that brought up this post and I thought it was rather elegant. Though perhaps a bit heavy on processing.
foreach ($array as $element)
{
if ($element === reset($array))
echo 'FIRST ELEMENT!';
if ($element === end($array))
echo 'LAST ELEMENT!';
}
Do note there is also a warning on the post that this will only work if the array values are unique. If your last element is "world" and some random element in the middle is also "world" last element will execute twice.
hm
<?php
$i = 0;
foreach($ar as $sth) {
if($i++ == 0) {
// do something
}
// do something else
}
more elegant.
first = true
foreach(...)
if first
do stuff
first = false
This is also works
foreach($array as $element) {
if ($element === reset($array))
echo 'FIRST ELEMENT!';
if ($element === end($array))
echo 'LAST ELEMENT!';
}
foreach($array as $element) {
if ($element === reset($array))
echo 'FIRST ELEMENT!';
if ($element === end($array))
echo 'LAST ELEMENT!';
}
Here's an example that does not use foreach loop
<?php
// A sample indexed array
$cities = array("London", "Paris", "New York");
echo $cities[0]; // Outputs: London
// A sample associative array
$fruits = array("a" => "Apple", "b" => "Ball", "c" => "Cat");
echo array_values($fruits)["0"]; // Outputs: Apple
?>
What about using key() native php function? which should work fine with all kind of arrays (indexed, associative ) as it will always return the first key no matter if its inside or outside the loop.
$array = array(
'One' => 'value',
'Two' => 'value-2',
'Three' => 'value-3',
);
foreach ( $array as $index => $key ) {
if ( key( $array ) ) {
/**Do something with the first key*/
} else {
/**Do something else*/
}
}
if it indexed array, you have many options you can go through,
for me using counter is always fine and get the correct result all the time.
$array = array(
'One',
'Two',
'Three',
);
$i = 0;
foreach ( $array as $index => $key ) {
if ( $array[ $i ] ) {
/**Do something with the first key*/
} else {
/**Do something else*/
$i++;
}
}
Both should work fine with $key => $value loop and it will only return the first key.
Also I would like to add something, You can always archive your target in scripting with hundreds of different way, Its all about the way you want to use in this situation.
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);