Multiple catch blocks in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of multiple catch blocks in PHP?

Multiple catch blocks allow you to handle different types of exceptions separately, providing specific responses for each exception type.

beginner

How do you write multiple catch blocks in PHP?

You write multiple catch blocks by following a try block with several catch blocks, each specifying a different exception type to handle.

intermediate

What happens if an exception is thrown that does not match any catch block?

If no catch block matches the thrown exception, the exception will remain unhandled and cause a fatal error unless caught elsewhere.

intermediate

Can you catch multiple exception types in a single catch block in PHP?

Yes, since PHP 7.1, you can catch multiple exception types in one catch block by separating them with a pipe (|) symbol.

beginner

Example: What will this code output?

try {
  throw new InvalidArgumentException('Invalid argument');
} catch (RuntimeException $e) {
  echo 'Runtime error';
} catch (InvalidArgumentException $e) {
  echo 'Invalid argument error';
}

The output will be: Invalid argument error because the thrown exception matches the second catch block.

What keyword starts the block where exceptions are caught in PHP?

A catch

B try

C throw

D finally

The catch keyword is used to define blocks that handle exceptions thrown in the preceding try block.

If an exception matches multiple catch blocks, which one runs?

A The first matching catch block

B The last matching catch block

C All matching catch blocks

D None, it causes an error

Only the first catch block that matches the exception type runs.

How do you catch multiple exception types in one catch block in PHP 8.0+?

A Use an array of types

B Use multiple catch blocks

C Separate types with commas

D Separate types with a pipe (|)

You separate exception types with a pipe (|) symbol inside a single catch block.

What happens if no catch block matches the thrown exception?

A The program continues normally

B The exception is ignored

C A fatal error occurs

D The exception is automatically caught

If no catch block matches, the exception is unhandled and causes a fatal error.

Which block always runs after try and catch blocks, regardless of exceptions?

A catch

B finally

C throw

D else

The finally block runs after try and catch blocks no matter what.

Explain how multiple catch blocks work in PHP and why they are useful.

Think about how you handle different problems separately in real life.

Describe how to catch multiple exception types in one catch block and when this might be helpful.

Imagine grouping similar problems to handle them together.