I ran across some example code that looks like this:
$form['#submit'][] = 'annotate_admin_settings_submit';
Why is there a bracket after ['#submit'] that is empty with nothing inside? What does this imply? Can anyone give me an example? Normally (from my understanding which is probably wrong) is that arrays have keys and in this case the the $form array key '#submit' is equal to 'annotate_admin_settings_submit' but what is the deal with the second set of brackets. I've seen examples where an array might look like:
$form['actions']['#type'] = 'actions';
I know this is a very basic question about php in general but I ran across this question while learning Drupal so hopefully someone in the Drupal community can clarify this question that I'm obsessing over.
When you say $form['actions']['#type'] = 'actions', it assigns a value to $form['actions']['#type'], but when you say $form['#submit'][] = 'annotate_admin_settings_submit', if $form['#submit'] is an array, it appends 'annotate_admin_settings_submit' to the end of it, and if it's empty, it will be an array with one single element that is 'annotate_admin_settings_submit'.
The empty brackets mean that when the string is added to the array, php will automatically generate a key for the entry instead of it being specified in the brackets when populating the array.
So $form['#submit'][] = 'annotate_admin_settings_submit'; is the same thing as $form['#submit'][0] = 'annotate_admin_settings_submit'; if it's the first time you do it.
Next time it will be $form['#submit'][1] = 'annotate_admin_settings_submit';, etc.
The empty bracket adds an auto increment index to an array. The new index will be +1 to the last index.
Please check this example.
$form['#submit'][0] = 'zero';
$form['#submit'][1] = 'One';
$form['#submit'][] = 'Two'; // this will be considered as $form['#submit'][2] = 'Two';
$form['#submit'][4] = 'Four';
$form['#submit'][] = 'Four'; //this will be considered as $form['#submit'][5] = 'Four'; since its adds 4(last index)+1
Related
This question already has answers here:
Notice: Undefined index when trying to increment an associative array in PHP
(6 answers)
Closed 4 months ago.
I want to increment a value of an array, which is potentially not existing yet.
$array = [];
$array['nonExistentYet']++; // Notice
Problem
This leads to a NOTICE.
Attempt
I found a way to do this, but its kinda clunky:
$array = [];
$array['nonExistentYet'] = ($array['nonExistentYet'] ?? 0) + 1;
Question
Is there a more human readable/elegant way to do this?
well i guess a more readable way would be to use if..else as,
$arr = [];
if(array_key_exists('nonExistentYet', $arr)) {
$arr['nonExistentYet'] += 1;
}
else {
$arr['nonExistentYet'] = 1;
}
If this is used often, you can define a little helper method, which also uses an interesting side effect...
function inc(&$element) {
$element++;
}
$array = [];
inc($array['nonExistentYet']);
print_r($array);
gives...
Array
(
[nonExistentYet] => 1
)
with no warning.
As you can see the function defines the parameter as &$element, if this value doesn't exist, then it will be created, so the function call itself will create the element and then it will just increment it.
My standard implementation for this is:
if (isset($array['nonExistentYet']))
$array['nonExistentYet']++;
else
$array['nonExistentYet'] = 1;
But this is one of the rarely scenarios where I use the # operator to suppress warnings, but only if I have full control over the array:
#$array['nonExistentYet']++;
Generally, it is not good to suppress warnings or error messages!
What you ask is a little vague,
Either the variable exists and you increment it, or it does not exist in this case you create it.
In another case suppose that you want to do it in a for loop, in this case you do not have to worry about the existence of the variable.
One way is ternary operator, which checks if array value exists:
$array['iDoNotExistYet'] = empty($array['iDoNotExistYet']) ? 1 : ++$array['iDoNotExistYet'];
Other one would be just rewriting it to if and else condition.
I'm kinda lost here.
So here is what i'm trying to do.
I have a session, that's called "test", i have set the session to be an array every time that $_POST['process'] isset.
The $_POST['process'] is containing a integer, that's fetched from a DB Table.
Here's my code:
if(isset($_POST['process']))
{
$_SESSION['test'] = array();
$array_merge = array_push($_SESSION['test'], $_POST['process']);
}
It work's at first time, here's the result:
[test] => Array
(
[0] => 21311
)
I was expecting, that it would create a new key, and assign it to the other value that get's fetched from $_POST['process'] - but instead it just overwrites the 0 key.
What am i doing wrong here?
Kind regards
In your code you're writing $_SESSION['test'] = array(); which is resetting the value of $_SESSION['test'] to an empty array. Therefore it has removed your previous value and have put in your new one.
To fix this check if $_SESSION['test'] is already set, if it's not do $_SESSION['test'] = array();, otherwise just insert new values.
Full example:
if(isset($_POST['process'])) {
if(!isset($_SESSION['test'])) {
$_SESSION['test'] = array();
}
$array_merge = array_push($_SESSION['test'], $_POST['process']);
}
Honestly, this is one precise case where using array_push() is a disadvantage versus its alternative square bracket syntax.
array_push() requires you to declare the empty array in advance; [] will not AND it is functionless AND it is more brief to code.
Furthermore, I am nearly 100% sure that you don't actually want to know the new element count after pushing. The PHP Manual says:
Returns the new number of elements in the array.
...so, if you do want to know the new count, then perhaps rename your variable from $array_merge to $array_size or $array_count or $array_length.
I know I wouldn't want to write an extra condition just to declare an empty variable then use a function to add a new element, especially when it can be done in one line
if(isset($_POST['process'])) {
$_SESSION['test'][] = $_POST['process']; // all done
}
This will work the first time and every time as desired.
This is honestly the most finicky and inept language I've ever coded in. I'll be glad when this project is good and over with.
In any case I have to us PHP so here's my question.
I have an Array named $form_data as such:
$form_data = array
('trav_emer_med_insur',
'trav_emer_single',
'trav_emer_single_date_go',
'trav_emer_single_date_ba',
'trav_emer_annual',
'trav_emer_annual_date_go',
'trav_emer_extend',
'trav_emer_extend_date_go',
'trav_emer_extend_date_ef',
'trav_emer_extend_date_ba',
'allinc_insur',
'allinc_insur_opt1',
'allinc_single_date_go',
'allinc_single_date_ba',
'allinc_insur_opt2',
'allinc_annual_date_go',
'allinc_annual_date_ba',
'cancel_insur',
'allinc_annual_date_go',
'allinc_annual_date_ba',
'visitor_insur',
'country_select',
'visitor_supervisa',
'visitor_supervisa_date_go',
'visitor_supervisa_date_ba',
'visitor_student',
'visitor_student_date_go',
'visitor_student_date_ba',
'visitor_xpat',
'visitor_xpat_date_go',
'visitor_xpat_date_ba',
'txtApp1Name',
'txtApp2Name',
'txtApp1DOB',
'txtApp2DOB',
'txtApp1Add',
'txtApp1City',
'selprov',
'txtApp1Postal',
'txtApp1Phone',
'txtApp1Ext',
'txtApp1Email',
'conpref', );
These are the names of name="" fields on an HTML form. I have verified that ALL names exist and have a default value of '' using var_dump($_POST).
What I want to do is very simple, using the $form_data as reference do this:
create a new array called $out_data which can handle the data to display on a regurgitated form.
The structure of $out_data is simple the key will be the name of the element from the other array $out_data[txtApp1Name] for example, and then the value of that key will be the value.
Now what I want is to first check to see if every name="" is set or not, to eliminate errors and verify the data. Then regardless of whether it is set or not, create its placeholder in the $out_data array.
So if $_POST[$form_data[1]] (name is 'trav_emer_single') is not set create an entry in $out_data that looks like this $out_data([trav_emer_single] => "NO DATA")
If $_POST[$form_data[1]] (name is 'trav_emer_single') is set create and entry in $out_data that looks like this: $out_data([trav_emer_single] => "whatever the user typed in")
I have tried this code:
$out_data = array();
$count = count($form_data);
for( $i = 0; $i < $count; $i++ )
{
if(!isset($_POST[$form_data[$i]])) {
$out_data[$form_data[$i]] = "NO_DATA";
}
else {
$out_data[$form_data[$i]] = $_POST[$form_data[$i]];
}
}
Now this code technically is working, it is going through the array and assigning values, but it is not doing so properly.
I have hit submit on the form with NOTHING entered. Therefore every item should say "NO_DATA" on my regurgitated output (for user review), however only some items are saying it. All items I have confirmed have name="" and match the array, and have nothing entered in them. Why is "NO_DATA" not being assigned to every item in the array?
Also of note, if I fill in the form completely $out_data is fully and correctly populated. What is the problem with !isset? I've tried doing $_POST[$form_data[$i]] == '' which does put no_data in every instance of no data, however it throws an 'undefined index' warning for every single item on the page whether I write something in the box or not.
Really I just want to know WTF is going on, the dead line for this project is closing fast and EVERY step of the PHP gives me grief.
As far as I can tell by reading around my code is valid, but refuses to execute as advertised.
If you need more code samples please ask.
Really befuddled here, nothing works without an error, help please.
Thanks
-Sean
Instead of checking !isset(), use empty(). If the form posts an empty string, it will still show up in the $_POST as an empty string, and isset() would return TRUE.
I've replaced your incremental for loop with a foreach loop, which is almost always used in PHP for iterating an array.
$out_data = array();
foreach ($form_data as $key) {
if(empty($_POST[$key])) {
$out_data[$key] = "NO_DATA";
}
else {
$out_data[$key] = $_POST[$key];
}
}
PHP's isset returns TRUE unless the variable is undefined or it is NULL. The empty string "" does not cause it to return FALSE. empty() will do exactly what you need, though.
http://php.net/manual/en/function.isset.php
isset() will return FALSE if testing a variable that has been set to
NULL. Also note that a NULL byte ("\0") is not equivalent to the PHP
NULL constant.
Returns TRUE if var exists and has value other than NULL, FALSE
otherwise.
I have an array with numerous dimensions, and I want to test for the existence of a cell.
The below cascaded approach, will be for sure a safe way to do it:
if (array_key_exists($arr, 'dim1Key'))
if (array_key_exists($arr['dim1Key'], 'dim2Key'))
if (array_key_exists($arr['dim1Key']['dim2Key'], 'dim3Key'))
echo "cell exists";
But is there a simpler way?
I'll go into more details about this:
Can I perform this check in one single statement?
Do I have to use array_key_exist or can I use something like isset? When do I use each and why?
isset() is the cannonical method of testing, even for multidimensional arrays. Unless you need to know exactly which dimension is missing, then something like
isset($arr[1][2][3])
is perfectly acceptable, even if the [1] and [2] elements aren't there (3 can't exist unless 1 and 2 are there).
However, if you have
$arr['a'] = null;
then
isset($arr['a']); // false
array_key_exists('a', $arr); // true
comment followup:
Maybe this analogy will help. Think of a PHP variable (an actual variable, an array element, etc...) as a cardboard box:
isset() looks inside the box and figures out if the box's contents can be typecast to something that's "not null". It doesn't care if the box exists or not - it only cares about the box's contents. If the box doesn't exist, then it obviously can't contain anything.
array_key_exists() checks if the box itself exists or not. The contents of the box are irrelevant, it's checking for traces of cardboard.
I was having the same problem, except i needed it for some Drupal stuff. I also needed to check if objects contained items as well as arrays. Here's the code I made, its a recursive search that looks to see if objects contain the value as well as arrays. Thought someone might find it useful.
function recursiveIsset($variable, $checkArray, $i=0) {
$new_var = null;
if(is_array($variable) && array_key_exists($checkArray[$i], $variable))
$new_var = $variable[$checkArray[$i]];
else if(is_object($variable) && array_key_exists($checkArray[$i], $variable))
$new_var = $variable->$checkArray[$i];
if(!isset($new_var))
return false;
else if(count($checkArray) > $i + 1)
return recursiveIsset($new_var, $checkArray, $i+1);
else
return $new_var;
}
Use: For instance
recursiveIsset($variables, array('content', 'body', '#object', 'body', 'und'))
In my case in drupal this ment for me that the following variable existed
$variables['content']['body']['#object']->body['und']
due note that just because '#object' is called object does not mean that it is. My recursive search also would return true if this location existed
$variables->content->body['#object']->body['und']
For a fast one liner you can use has method from this array library:
Arr::has('dim1Key.dim2Key.dim3Key')
Big benefit is that you can use dot notation to specify array keys which makes things simpler and more elegant.
Also, this method will work as expected for null value because it internally uses array_key_exists.
If you want to check $arr['dim1Key']['dim2Key']['dim3Key'], to be safe you need to check if all arrays exist before dim3Key. Then you can use array_key_exists.
So yes, there is a simpler way using one single if statement like the following:
if (isset($arr['dim1Key']['dim2Key']) &&
array_key_exists('dim3Key', $arr['dim1Key']['dim2Key'])) ...
I prefer creating a helper function like the following:
function my_isset_multi( $arr,$keys ){
foreach( $keys as $key ){
if( !isset( $arr[$key] ) ){
return false;
}
$arr = $arr[$key];
}
return $arr;
}
Then in my code, I first check the array using the function above, and if it doesn't return false, it will return the array itself.
Imagine you have this kind of array:
$arr = array( 'sample-1' => 'value-1','sample-2' => 'value-2','sample-3' => 'value-3' );
You can write something like this:
$arr = my_isset_multi( $arr,array( 'sample-1','sample-2','sample-3' ) );
if( $arr ){
//You can use the variable $arr without problems
}
The function my_isset_multi will check for every level of the array, and if a key is not set, it will return false.
Can this be done in 1 line with PHP?
Would be awesome if it could:
$out = array("foo","bar");
echo $out[0];
Something such as:
echo array("foo","bar")[0];
Unfortunately that's not possible. Would it be possible like this?
So I can do this for example in 1 line:
echo array(rand(1,100), rand(1000,2000))[rand(0,1)];
So let's say I have this code:
switch($r){
case 1: $ext = "com"; break;
case 2: $ext = "nl"; break;
case 3: $ext = "co.uk"; break;
case 4: $ext = "de"; break;
case 5: $ext = "fr"; break;
}
That would be much more simplified to do it like this:
$ext = array("com","nl","co.uk","de","fr")[rand(1,5)];
Why not check out the array functions on the PHP site?
Well, if you're picking a random element from the array, you can use array_rand().
$ext = array_rand(array_flip(array("com","nl","co.uk","de","fr")));
echo array_rand(array_flip(array('foo', 'bar')));
array flip takes an array and swaps the keys with the values and vice versa. array_rand pulls a random element from that array.
You can use a shorthand form to keep things on one line and avoid creating an array that will never be used again.
echo rand(0,1) ? rand(1,100) : rand(1000,2000);
Yes, list a PHP language construct that allows the syntax below.
list( $first_list_element ) = array( "foo", ..... );
EDIT:
Still Yes, Missed the echo. Reset will return the first array item, which might not always be index 0, but if you create an array normally it will.
echo reset( array( "foo",... ) );
EDIT AGAIN:
After you updated your question I see that you want something that PHP just can't do well. I personally think it's a syntax design error of the PHP language/interpreter. If you just mean one-line you could do.
$array = array( .... ); echo $array[0];
I think your example may not be the best. The real syntax limitation here is that one can not immediately perform array access on the returned value of a function call, as in,
do_something_with(explode(',', $str)[0]);
And you pretty much can't get around it. Assign to a variable, then access. It's a silly limitation of PHP, but it's there.
You can technically do,
function array_access($array, $i) {
return $array[$i];
}
do_something_with(array_access(explode(',', $str), 0));
But please don't. It's even uglier than an extra variable asignment.
(Given the edit to the question, this no longer a sufficient answer. However, I will leave it up for reference.)
Like #Matchu's answer, this addresses the more general case, ie you have an array value that came from somewhere, be it a function call, an instantiated array, whatever. Since the return value from an arbitrary function is the least specific case, I'll use a call to some_function() in this example.
$first_element = current(array_slice(some_function(), 0, 1));
So you could randomize it with
$random_element = current(array_slice(some_function(), rand(0,1), 1));
but in that case (as in many in php) there is a more specialized function for that; see #animuson's answer.
edited
changed array_shift() call to current() call: this is more efficient, because array_shift() will modify the intermediate array returned by array_slice().
This is being discussed in the internals mailing list right now. You might want to check it: http://marc.info/?l=php-internals&m=127595613412885&w=2
print $a[ array_rand($a = array('com','nl','co.uk','de','fr')) ];