Продолжить текущую итерацию в блоке try-catch | PHP
В моем скрипте иногда есть проблемы с сервером, соединением, конфигурацией или API, поэтому я реализовал блок try-catch, чтобы правильно поймать исключения и пропустить их.
. но моя проблема не решена с этим решением, поскольку элементы (которые бросили проблему) не являются самой проблемой. Итак, в основном мой вопрос : есть ли способ отловить ошибку и продолжить, где вы оставили: не пропустить ошибку и перейти к следующему элементу, а повторить текущую итерацию в цикле foreach.
Очевидно, continue и break не работают!
foreach($xx as $x) < try < //main code >catch (Exception $e) < echo 'Caught exception: ', $e->getMessage(), "\n"; sleep(10); > > . и когда улов часть ловит ошибку код должен повторить цикл попытки с текущей $x (на которой он первоначально поймал ошибку / бросил ошибку), а затем продолжить список элементов.
3 ответа
Поместите блок try в его собственный цикл while (true) , который вы можете break в случае успеха:
Это повторяет одно и то же действие, пока не будет выдано исключение. Чтобы избежать бесконечных циклов действий, которые просто никогда не будут успешными, вы можете добавить счетчик, например:
Как только исключение выдается и перехватывается, пути назад к блоку кода, в котором было сгенерировано исключение, больше нет. Настолько неудачно, что нет технической возможности, что у вас есть только один блок try catch, в котором вы перехватываете все исключения и затем решаете, являются ли они важными (и прекращают ли выполнение сценария), или исключение не было реальной проблемой, и вы хотите, чтобы ваш сценарий вел себя как если бы не было исключения.
Единственное решение, которое я могу дать вам:
foreach($xx as $x) < try < //main code try < //first code that can cause an exception //you just want to continue after >catch (Exception $e) < echo "Nothing wrong, just an exception " . $e->getMessage(), "\n"; > try < //second code that can cause an exception //a serious problem, you don't want to continue >catch (Exception $e) < echo "This is a real problem " . $e->getMessage(), "\n"; throw $e; //re-trowing exception > //third code that can cause an exception > catch (Exception $e) < //will catch exception from code 2 and 3 but not 1. echo 'Caught exception: ', $e->getMessage(), "\n"; sleep(10); > > КСТАТИ . То, что вы просите, должно быть сделано не с использованием исключений, а в случае ошибок. Если об ошибке сообщается, и она может быть исправлена, вы можете написать глобальный обработчик для ошибок, и внутри этого дескриптора ошибки решить, является ли ошибка проблемой, вы хотите закрыть свой сценарий или просто зарегистрировать его и вернуться к выполнению сценария, как если бы Там нет ошибки вообще. Но это ошибки, а не исключения.
Вы можете запустить цикл вместо цикла foreach и управлять счетчиком приращений внутри блока catch, уменьшив его, чтобы получить текущий $ x (для которого он первоначально перехватил ошибку / сгенерировал ошибку) и снова повторить попытку с тем же элементом. Это может вызвать бесконечный цикл, поэтому сохраняйте любой порог повторной попытки.
Code Example: Implementing ‘Continue’ in PHP Try-Catch Block
To prevent infinite loops that are bound to fail, you can incorporate a counter into your code. Alternatively, instead of using a foreach loop, try using a for loop and manage the increment counter within the catch block. Decrease the counter to retrieve the current element that caused the error and retry with it. As a result, the output will not include the failed element, but rather start incrementing from the next element and continue until the end of the loop condition. Finally, the program will print «End of for loop» to indicate that it has exited the for loop.
How to try-catch and continue the script in php
To prevent the script from breaking, it is advisable to use a separate loop for the try-catch block and include the continue keyword.
$success=false; $cattempt=0;// current attempt; while($cattempt<=2)< try< sleep(2); $xml = simplexml_load_string($formattedResponse); $success=true; >catch (\GuzzleHttp\Exception\ServerException $e) < $code=$e->getResponse()->getStatusCode(); echo "Error: ".$e->getResponse()->getReasonPhrase()." Code: ".$code."
"; switch($code)< // throttle request/service unavailable; case 503: sleep(2); $cattempt++; // will try again. break; // break from switch default: // sleep(2); // $cattempt++; break 2; // break from swtich and while loop // throw new Exception($e->getResponse()->getReasonPhrase(),$code); > > catch (\Exception $e) < echo "Error: ".$e->getMessage()." Code: ".$e->getCode()."
"; sleep(2); break; // break from while; // throw new Exception($e->getMessage(),$e->getCode()); > if($success) break; > if(!$success) < continue; // go to next ASIN. >Php: catch exception and continue execution, is it, php: catch exception and continue execution, is it possible? b depends on some result of a it makes no sense to put b after the try-catch block. Share. Follow It should be emphasized again that it’s important to do something meaningful, in most cases, inside the catch. Otherwise the code just breaks and … Code sampletry catch (SomeException $e) <>Feedback
Continue with current iteration in a try-catch block
Isolate the try block within a designated while (true) iteration, where you have the option to break upon successful execution.
To prevent infinite looping on actions that are bound to fail, you can incorporate a counter while retrying the action until no exceptions are thrown.
Instead of using a foreach loop, you can utilize a for loop and handle the increment counter within the catch block. To retrieve the current $x that caused the error, decrement the counter and retry the same element. However, setting a threshold for the number of retries is advisable to avoid an infinite loop.
When an exception is caught, it is not possible to return to the code block where the exception was thrown. Therefore, having a single try-catch block to catch all exceptions and deciding their importance is not technically feasible. If an exception is not a significant issue, and you want your script to proceed without any disruption, this approach is not suitable.
The sole resolution that I can provide to you is:
foreach($xx as $x) < try < //main code try < //first code that can cause an exception //you just want to continue after >catch (Exception $e) < echo "Nothing wrong, just an exception " . $e->getMessage(), "\n"; > try < //second code that can cause an exception //a serious problem, you don't want to continue >catch (Exception $e) < echo "This is a real problem " . $e->getMessage(), "\n"; throw $e; //re-trowing exception > //third code that can cause an exception > catch (Exception $e) < //will catch exception from code 2 and 3 but not 1. echo 'Caught exception: ', $e->getMessage(), "\n"; sleep(10); > > By the way, the task you are requesting cannot be accomplished through exceptions. If an error is detected and it can be fixed, you can establish a general error handler to determine if the error is critical enough to halt the script or simply record it and continue the script execution as if there was no error. However, it is essential to note that this pertains to errors, not exceptions.
How to try-catch and continue the script in php, How to try-catch and continue the script in php. Ask Question Asked 5 years, 8 months ago. Modified 5 years, 8 months ago. Viewed 1k times -1 I am querying an API but some times the API sends 503, 400 etc errors after random hours of script execution. Try-catch speeding up my code? 2210. How does …
Continue in PHP
Introduction to Continue in PHP
The continue statement is employed within conditional statements to direct the code to skip the current iteration of the loop and proceed with executing the condition evaluation, then jump to the beginning of the next iteration. In PHP, the switch statement is where the continue statement is most frequently utilized.
The ‘continue’ statement can have an optional numerical value, which specifies the number of internal loops to skip and move to the end of. This means that if the value is set to 1, it will skip to the end of the current loop. Unlike the ‘break’ statement, which ends the loop entirely, ‘continue’ is used to move on to the next loop as a shortcut. Both ‘continue’ and ‘break’ provide additional control to the programmer over the loops and allow them to manipulate them as needed.
while ( condition 1) < //declaration statements if ( condition 2 ) < //PHP code goes here continue ; >// Operational Statements >Initially, a while loop is declared with a condition. The code enters the loop while the condition is true and exits when it’s false. If the condition of the if statement is true, the code enters its loop. However, by using the continue statement, the iteration is skipped, and the later part of the code is not executed. As a result, the control is transferred to the next iteration of the while loop, which has a condition of 1.
Flowchart
Here is a PHP flowchart that illustrates the process of continuing.
Within the code block where the loop is running, there is consistently a continue statement present, as shown in the flowchart. In the event that the condition for the continue statement is satisfied, the following action is bypassed and the loop moves on to the next iteration.
Examples of Continue in PHP
Let’s gain a better understanding of the functionality of continue statements through a few thorough examples provided below.
Example #1
This program starts by setting variable a to zero, followed by using a for loop to increase its value by one until it reaches 10. To prevent the loop from continuing after a equals 4, we have included a conditional statement with a break statement. Instead of printing the value 5, the program prints «End of the loop» and stops at 4, which is the last value that was incremented. This is done to help us better understand the output, which shows each incremented value.
Now, let’s observe the effect of the continue statement on the aforementioned code.
The program output above displays the numbers 0 to 4, similar to the previous output. However, when the if conditional statement was TRUE, the continue statement allowed the loop to skip printing 4 and continue. As a result, the output did not show 4, but instead continued incrementing from 5 to 10, which met the for loop condition. Finally, the program printed “End of for loop” to indicate that it had exited the for loop. Therefore, the continue statement is commonly used to skip a particular instance and continue the loop from the next.
Example #2
$val) < if (!($k % 2)) < // skip even members continue; >do_something_odd($val); > $j = 0; while ($j++ < 5) < echo "Outermost while loop\n"; while (1) < echo "Middle while loop\n"; while (1) < echo "Innermost while loop\n"; continue 3; >echo "This text will never get printed\n"; > echo "This text also will never get printed\n"; > ?> 
Within the provided code, variable k is utilized in the if conditional loop to bypass even numbers through implementation of the modulo 2 function. By incorporating the continue statement, the current iteration is skipped, resulting in an absence of output.
During the second part of the loop, we initialize variable j to zero and utilize it. We employ three while loops: an outermost loop, a middle loop, and an innermost loop. The outermost loop executes when j is less than 5 and increments j by 1. The middle and inner loops run indefinitely, without any conditions.
Similar to the break statement, numeric parameters can also be passed with the continue statement. In the above example, the number 3 is passed, which skips 3 loop iterations, resulting in the omitted text shown in the code. By using continue 2, the innermost and middle while loops are skipped, and the last text is printed. Likewise, continue 1 skips only the innermost loop. However, it should be noted that continue 0 is no longer a valid statement, even though it was previously considered the same as continue 1.
Example #3
One can also utilize «continue» within a switch statement in the following manner:
The behavior of break and continue statements in switch statements is similar to that in loops, where they are used to terminate the current iteration and move on to the next. If we use continue 2 within a switch inside a loop, we can exit the switch and continue with the next outer loop iteration.
Importance of Continue in PHP
- The primary objective of using the continue statement within loops is to skip a specific iteration that the programmer desires.
- When using a do-while loop, the continue statement assumes responsibility for the while loop’s conditional statement.
- The control of the while loop’s condition is once again taken by the continue, even within the while loop.
- The actions of incrementing or decrementing in a for loop are executed following the continue statement.
Drawbacks of Using Continue Statement in PHP
- An error will occur if we attempt to use the keyword «continue» in a file name that is within a loop.
- Employing the continue statement in code can make it difficult to comprehend and appear inelegant.
Conclusion – Continue in PHP
In programming, continue statements are commonly employed in loops and conditional statements in php to halt the current iteration without ending the loop altogether. When a continue statement is encountered within the block of statements, it simply skips to the next iteration that satisfies the conditional statement.
Final thoughts
In this article, we have provided a comprehensive guide on how to use the Continue statement in PHP. We covered its syntax, importance, and shared several examples to help you understand its usage. For further learning, you can check out the related articles mentioned below.
Continue with current iteration in a try-catch block, @DoakCode Probably I wrongly understood your intention, with the @deceze solution you still get your code interrupted, and after the first exception let say at the line 20 of your code you will never execute line 21, 22, and all the rest of code unless there is no exception thrown at the line 20 or you put the line 20 …