$pairs = []; // Clear the pairs array
$pairs['post_name'] = $post->post_name; // Hold the post_name for the error function's use
$pairs['post_id'] = $post->ID; // Hold the post ID for the error function's use
$pairs['tag'] = $tag; // Add the tag to the pairs array for the error function's use
The above is code to define an array then set a few values. This is throwing an error that I suspect is complaining because I didn't pre-define the keys, but I also don't want to. One of the biggest advantages of PHP is that it's not necessary to pre-define and allocate every little thing when it's obvious from context.
Is there a simple way of solving this problem without having to predefine the entire array and all it's keys? I tried changing the definition to $pairs = {} on the hopes it would be happier, but no dice. I suspect this is a problem with updating to PHP 8 and am tempted to turn off warnings, but would rather do it "right" (unless that means predefining everything).
EDIT: TO be clear, the error listed in the title applies to ALL of the above assignments and any other similar assignments in my code. I'm getting a hundred or more instances of this error because I've always created array keys on assignment like this before and I'd like to keep doing so.
Related
Cutting out some of the code on the innermost foreach, I'm trying to change HERE to make it so that it alters the original value. I want to pass a pointer basically and alter it. I was able to kind of do this with the &$ keyword in the foreach but (as the docs state) it results in some buggy behavior and I'm trying to do it the way they, and others on SO suggest. The problem is all the examples I find are for a single foreach, not for nested.
The following code loops properly but when I get to the HERE it doesn't actually alter the original value. Also worth mentioning that $sources could be an array of arrays (by index) or an array of key values. This looping code seems to iterate over both fine though, just not overriding the original value of $sources
fwiw, on top of the &$ I also tried:
$sources[$sourceKey][$rowKey][$cellKey] = $date->format('m/d/Y');
Which $sources[$sourceKey][$rowKey][$cellKey] returns the right value if I print it but it still doesn't overwrite the original array.
function convertDates($sources) {
foreach($sources as $sourceKey => $sourceValue){
foreach ($sourceValue as $rowKey => $rowValue) {
foreach ($rowValue as $cellKey => $cellValue) {
HERE = $date->format('m/d/Y');
}
}
}
}
I never could get this to work correctly since there were two formats this loop could get (JSON encoded object and an array). Making it work for both was much harder than just doing it in JavaScript so instead of modifying on the server I format the data how I want client side and send it up. This formatting is purely presentational and for personal use so if someone were to put in a debugger and change the code to send a different format thats fine and there's no security issues.
So in the end, this code was rewritten in JS and since JS handles arrays and objects using the same pointers the above issue wasn't an issue any longer.
Let's say I have a variable which is an initialized, empty array.
$cache = [];
The data in this array can be created like this, for example (please excuse the crude code and variable/key names, they're here for the sake of this example only):
for ($row in $someOtherArray) {
$cache[$row['id']][] = $row['data'];
}
Since $cache is a PHP array, I don't really need to initialize $cache[$row['id']] to also be an array. However, I sometimes encounter code like this:
for ($row in $someOtherArray) {
if (!isset($cache[$row['id']])) {
$cache[$row['id']] = [];
}
$cache[$row['id']][] = $row['data'];
}
Above, the sub-array is explicitly initialized as an empty array. Is it useful somehow? For example - does it help the interpreter in some way? Or is it only a developer being overzealous?
It's unnecessary as far as PHP is concerned. PHP will implicitly create any number of sub-arrays for you using the $foo[$bar][] syntax. It may be required for business logic, though not in this particular arrangement; it's simply redundant here. If the value assignment is somehow separate logic, but you still want to ensure that at least an empty array exists for the key, that's the only time it makes sense.
Once you have initialised a variable as an array, you can use array specific methods on that variable. For example array_push(), array_map() etc..
$q2=$_REQUEST['binge'];
'book2'=>array('callno'=>123006,'price'=>number_format(844,2),'desc'=>'Binge','auth'=>'Tyler Oakley','quant'=>$q2,'total'=>number_format(844,2)*$q2)
On this particular code, It kept displaying errors like this
Warning: A non-numeric value encountered in C:\xampp\htdocs\Webcard_3new\Webcard\wishlist.php on line 97
I searched all over the net for finding the right answers but some are just so complex to understand...
It supposed to be that $q2 is the variable inside an array. That variable is then multiplied to the "TOTAL". but the errors kept on going.. please help!!
The super-globals will always be strings. You need to explicitly convert them using intval():
$q2 = intval($_REQUEST['binge']);
Also, this line:
'book2'=>array...
Should be
$book2 = array...
You can use
$q2 = filter_var($_REQUEST['binge'], FILTER_VALIDATE_INT);
here you will have the benefit of validation where false is returned when someone passes a value that is not an integer. If it is instead a float use FILTER_VALIDATE_FLOAT instead.
Also, consider using $_GET, or $_POST directly to have more control of the data channel. $_REQUEST cobbles together several things into one, which sometimes may cause issues when more than one channel have the same key.
One thing that's always bugged me (and everyone else, ever) about PHP is its inconsistency in function naming and parameters. Another more recent annoyance is its tendency to ask for function parameters by reference rather than by value.
I did a quick browse through the PHP manual, and found the function sort() as an example. If I was implementing that function I'd take an array by value, sort it into a new array, and return the new value. In PHP, sort() returns a boolean, and modifies the existing array.
How I'd like to call sort():
$array = array('c','a','b');
$sorted_array = sort($array);
How PHP wants me to call sort():
$array = array('c','a','b');
sort($array);
$sorted_array = $array;
And additionally, the following throws a fatal error: Fatal error: Only variables can be passed by reference
sort(array('c','a','b');
I'd imagine that part of this could be a legacy of PHP's old days, but there must have been a reason things were done this way. I can see the value in passing an object by reference ID like PHP 5+ does (which I guess is sort of in between pass by reference and pass by value), but not in the case of strings, arrays, integers and such.
I'm not an expert in the field of Computer Science, so as you can probably gather I'm trying to grasp some of these concepts still, and I'm curious as to whether there's a reason things are set up this way, or whether it's just a leftover.
The main reason is that PHP was developed by C programmers, and this is very much a C-programming paradigm. In C, it makes sense to pass a pointer to a data structure you want changed. In PHP, not so much (Among other things, because references are not the same as a pointer).
I believe this is done for speed-reason.
Most of the time you need the array you are working on to be sorted, not a copy.
If sort should have returned a new copy of the array then for each time you call sort(); the PHP engine should have copied the array into new one (lowering speed and increasing space cost) and you would have no way to control this behaviour.
If you need the original array to be not sorted (and this doesn't happen so often) then just do:
$copy = $yourArray;
sort($yourArray);
this is my first question.
I am doing some optimizations on a php script, improving its speed of execution...
Between :
$datas = array();
$datas['file_import'] = $file_name_reporting;
And :
unset($datas);
$datas['file_import'] = $file_name_reporting;
Can someone tell me which one is faster ?
Thank you
Your second example causes warning, because $datas is right now null and you are treating it as an array, so you have to declare it as an empty array before.
So just follow your first example - assign an empty array and then put into it some data.
array() will create an array whereas unset() will destroy a variable.
I think first method is just a overwriting but second one includes deleting, checking existence, triggering warning and creating new array
It's ridiculous to claim that either form is "faster" than the other. Both versions will execute so fast that you would need to run them millions of times inside a loop to perhaps notice a difference. Do you actually do that inside your script? If not, forget about "optimization" here (actually, it would be a good idea to forget about all optimization "by eye", as any experienced developer can tell you).
On top of that, the two versions actually do different things, in that unset will remove the name $datas from the sumbol table (and give you a notice in the next line when you attempt to add a value to an array).
Just use what feels right, and look inside heavy loops to find something to optimize.
In both cases, a new Array will be constructed. Unsetting a variable in php, will set it's value to null, only to call the array constructor on the next line. Although I agree with knittl, my suggestion would be:
$datas = array('file_import' => $file_name_reporting);
By creating a new array, you automatically 'unset' the variable, and by passing values to the array constructor, you can fill your array with whatever values you want while you're at it.
Obviously the first code will work faster because you do only two operations: explicitly create an array and add a portion of data. The second example will cause a warning because you destroy a variable and then try to use it again.
Additionally unset will not release used memory, it will only release a pointer on variable. Memory will be released when gc will be runned. To release a memory, use $datas = null; instead.