![]() ![]() If the exception triggers, an exception is "thrown". If the exception does not trigger, the code continues as normal. Try: The try block is used to run any code that is expected to fail in an exceptional case (throwing an exception error). PHP tries to find the matching "catch" block. If an exception is not caught, a fatal error is issued with an "Uncaught Exception" message. To avoid the error, you need to create the proper code to handle an exception. When an exception is thrown, the code following it is not executed. This list of functions is known as the call stack. This place that is looked for is called the exception handler, and it will be searched for in the list of functions that are called in the current runtime, until the exception was thrown. When the exception is thrown, it is handed to the runtime system, which will try to find a place in the script where the exception can be handled. We can throw and catch exceptions in a PHP script. When an error occurs, it is transformed into an object (the exception object) that contains relevant information about the error and the location where it was triggered. Exception handling is used to change the normal flow of the code execution if a specified error (exceptional) condition occurs. Exceptions are used to change the normal flow of a script if a specified error occurs.Īn exception is an event that occurs during the runtime of a program, and that disrupts its normal flow. PHP 5 introduced new object oriented way of dealing with errors. This will help you detect and recover from unexpected errors in your application.PHP provides an error-handling class called Exception. For example, if you opened a database connection or file on disk in a try block, you can perform cleanup tasks such as closing the connection in a finally block, as this is guaranteed.Įxception handling is a key coding skill, and you should consider how exceptions will be handled as you develop your applications. The typical use cases we could come up with for using a finally block are usually related to resource cleanup. And, as we discussed, the code in this block will always be executed. The code in the above example is almost the same with the only exception that we have added a finally block after the catch block. Let’s take a look at the following diagram, which shows the general control flow of exception handling. And an exception that doesn’t hit anywhere in your application results in an error that stops the program from running. If the exception being thrown is somewhere in your application, program execution continues from where the exception was caught. So we can say that exceptions are recoverable and not certain errors that are not recoverable. On the other hand, exceptions are something that is deliberately thrown by code and is expected to be caught at some point in your application. However, as a rule, some kinds of errors are not recovered and stop the program execution. When handling errors, we can use the set_error_handler function to set our custom error handling function so that whenever an error is fired, it will call our error handling function. It is important to note here that exception handling is different from error handling. All exceptions are instances of the Exception base class, which we can extend to introduce our own custom exceptions. This model allows you to throw and catch exceptions in your application - it’s a better way to handle errors than older versions of PHP. ![]() PHP 5 introduced us to a new error model that is still evolving today.
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