Error vs Exception in PHP - Practice Questions

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of error and exception handling

What will be the output of this PHP code snippet?

PHP

<?php
function test() {
    try {
        throw new Exception("Exception caught");
    } catch (Error $e) {
        echo "Error caught";
    } catch (Exception $e) {
        echo $e->getMessage();
    }
}
test();

A Error caught

B Fatal error

C Exception caught

D No output

💡 Hint

Remember that Exception and Error are different classes in PHP and catch blocks handle exceptions based on type.

The thrown Exception is caught by the catch block for Exception, so it prints 'Exception caught'. The catch block for Error is skipped because the thrown object is not an Error.

❓ Predict Output

intermediate

Behavior of uncaught Error

What happens when this PHP code runs?

PHP

<?php
function test() {
    try {
        undefinedFunction();
    } catch (Exception $e) {
        echo "Exception caught";
    }
}
test();

A Warning but script continues

B Exception caught

C No output

D Fatal error: Uncaught Error: Call to undefined function

💡 Hint

Undefined functions cause Errors, not Exceptions.

Calling an undefined function throws an Error, which is not caught by the catch block for Exception, so a fatal error occurs.

🔧 Debug

advanced

Identify the error type caught

What type of error or exception is caught by this code?

PHP

<?php
try {
    $arr = [];
    $arr[5]();
} catch (Error $e) {
    echo get_class($e);
} catch (Exception $e) {
    echo get_class($e);
}

A ErrorException

B Error

C Exception

D UndefinedOffsetException

💡 Hint

Accessing an undefined array index triggers a specific error type in PHP 7+.

Accessing an undefined array index throws an Error of type Error, not Exception or ErrorException.

📝 Syntax

advanced

Which catch block order is correct?

Given that Error and Exception are both throwable in PHP, which catch block order will NOT cause a fatal error?

PHP

try {
    // some code
} catch (___) {
    // handle
} catch (___) {
    // handle
}

A catch (Error $e) then catch (Exception $e)

B catch (Exception $e) then catch (Error $e)

C catch (Exception $e) then catch (Throwable $t)

D catch (Throwable $t) then catch (Exception $e)

💡 Hint

More specific exceptions must be caught before more general ones.

Error and Exception both implement Throwable. Catching Error before Exception is correct because they are siblings. Catching Throwable before Exception causes unreachable code error.

🧠 Conceptual

expert

Difference between Error and Exception in PHP

Which statement best describes the difference between Error and Exception in PHP?

A Errors represent serious problems from PHP engine or environment, Exceptions represent user-defined or runtime issues that can be caught and handled.

B Errors and Exceptions are identical and interchangeable in PHP.

C Errors represent fatal problems that cannot be caught, Exceptions represent recoverable problems that can be caught.

D Exceptions are only for syntax errors, Errors are for runtime errors.

💡 Hint

Think about what kind of problems each class represents and how PHP treats them.

Errors represent serious problems like engine failures or type errors, while Exceptions are for user-defined or runtime issues that can be caught and handled by the program.