Try-catch execution flow in PHP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of try-catch with exception thrown

What is the output of this PHP code?

PHP

<?php
try {
    echo "Start\n";
    throw new Exception("Error happened");
    echo "End\n";
} catch (Exception $e) {
    echo "Caught: " . $e->getMessage() . "\n";
}
?>

A

Caught: Error happened
Start

B

Start
End
Caught: Error happened

C

Start
End

D

Start
Caught: Error happened

💡 Hint

Remember that code after throw inside try block is not executed.

The code prints "Start" first. Then the exception is thrown, so the line printing "End" is skipped. The catch block runs and prints the exception message.

❓ Predict Output

intermediate

Output when no exception is thrown

What will this PHP code output?

PHP

<?php
try {
    echo "Before\n";
    // no exception thrown
    echo "After\n";
} catch (Exception $e) {
    echo "Caught\n";
}
?>

A

Before
After

B

Before
Caught

C

Caught
After

D

After

💡 Hint

If no exception is thrown, catch block is skipped.

Since no exception is thrown, both echo statements inside try run normally and catch block is ignored.

❓ Predict Output

advanced

Output with finally block execution

What is the output of this PHP code?

PHP

<?php
try {
    echo "Try block\n";
    throw new Exception("Oops");
} catch (Exception $e) {
    echo "Catch block\n";
} finally {
    echo "Finally block\n";
}
?>

A

Try block
Catch block

B

Try block
Finally block
Catch block

C

Try block
Catch block
Finally block

D

Catch block
Finally block

💡 Hint

Finally block always runs after try and catch.

The try block runs and throws an exception. The catch block handles it. Finally block runs regardless of exception.

❓ Predict Output

advanced

Output when RuntimeException is thrown

What is the output of this PHP code?

PHP

<?php
try {
    echo "Start\n";
    throw new RuntimeException("Runtime error");
} catch (Exception $e) {
    echo "Caught Exception\n";
}
?>

A

Start
Caught Exception

B

Start
Fatal error: Uncaught RuntimeException

C

Caught Exception

D

Start

💡 Hint

RuntimeException extends Exception, so catch(Exception $e) catches it.

The code prints "Start". Then RuntimeException is thrown, which is caught by catch(Exception $e) since RuntimeException extends Exception. It prints "Caught Exception".

❓ Predict Output

expert

Output with nested try-catch and rethrow

What is the output of this PHP code?

PHP

<?php
try {
    try {
        echo "Inner try\n";
        throw new Exception("Inner error");
    } catch (Exception $e) {
        echo "Inner catch\n";
        throw $e;
    } finally {
        echo "Inner finally\n";
    }
} catch (Exception $e) {
    echo "Outer catch\n";
} finally {
    echo "Outer finally\n";
}
?>

A

Inner try
Inner catch
Outer catch
Inner finally
Outer finally

B

Inner try
Inner catch
Inner finally
Outer catch
Outer finally

C

Inner try
Inner finally
Inner catch
Outer catch
Outer finally

D

Inner try
Inner catch
Inner finally
Outer finally

💡 Hint

Remember finally blocks run before control leaves the try or catch blocks.

The inner try throws an exception. Inner catch runs and rethrows. Inner finally runs before exception propagates. Outer catch catches the rethrown exception. Outer finally runs last.