I retrieve a laravel collection from a database on which I want to update certain values based on three calculations. But before I do the calculations I first check if all the relevant collection items is not null. I can check if they are null but for some reason cannot rerieve an error variable that has Controller function scope to tell a user that a variable has not been set.
$error_arr = [];
$calculation = FertilApp::calculation($product, $farm, $agent);
$calculation->each(function ($item, $key) {
if ($item->ha === null) {
$error_arr[] = 'Prices has been updated';
$error_arr[] = 'But no calculation has been done, please update following block:' . $item->block;
return false;
}
});
The variable$error_arr
returns an empty array even though I know theha
key isnull
.
The alternative is to use a normalforeach()
loop. I have tried it and it works, but I really want to know why this is not working.
Can someone please help to give me a clue to why this collectioneach()
method is denying my variable access to values from outside the collection method?
EDIT: If I try to pass my variable as a parameter I get the following error messageCannot use a scalar value as an array
.
Laravel version: 5.6.39
Try aglobal
statement:
$calculation->each(function ($item, $key) {
global $error_arr;
$error_arr
is empty in your code, because it doesn't exist in the scope of the callbackfunction
of youreach
method. Unlike other languages ??“? like JavaScript ??“? variables outside a function aren't accessible by default inside the function. See PHP's documentation on variable scope for details.
Our community is visited by hundreds of web development professionals every day. Ask your question and get a quick answer for free.
Find the answer in similar questions on our website.
Do you know the answer to this question? Write a quick response to it. With your help, we will make our community stronger.
PHP (from the English Hypertext Preprocessor - hypertext preprocessor) is a scripting programming language for developing web applications. Supported by most hosting providers, it is one of the most popular tools for creating dynamic websites.
The PHP scripting language has gained wide popularity due to its processing speed, simplicity, cross-platform, functionality and distribution of source codes under its own license.
https://www.php.net/
Laravel is a free open source PHP framework that came out in 2011. Since then, it has been able to become the framework of choice for web developers. One of the main reasons for this is that Laravel makes it easier, faster, and safer to develop complex web applications than any other framework.
https://laravel.com/
JavaScript is a multi-paradigm language that supports event-driven, functional, and mandatory (including object-oriented and prototype-based) programming types. Originally JavaScript was only used on the client side. JavaScript is now still used as a server-side programming language. To summarize, we can say that JavaScript is the language of the Internet.
https://www.javascript.com/
Welcome to the Q&A site for web developers. Here you can ask a question about the problem you are facing and get answers from other experts. We have created a user-friendly interface so that you can quickly and free of charge ask a question about a web programming problem. We also invite other experts to join our community and help other members who ask questions. In addition, you can use our search for questions with a solution.
Ask about the real problem you are facing. Describe in detail what you are doing and what you want to achieve.
Our goal is to create a strong community in which everyone will support each other. If you find a question and know the answer to it, help others with your knowledge.