Heredoc and nowdoc syntax in PHP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a heredoc string with variable interpolation

What is the output of this PHP code?

PHP

<?php
$name = "Alice";
$text = <<<EOD
Hello, $name!
Welcome to PHP.
EOD;
echo $text;

A Hello, Alice! Welcome to PHP.

B

Hello, $name!
Welcome to PHP.

C

Hello, Alice!
Welcome to PHP.

D Syntax error

💡 Hint

Heredoc strings allow variable interpolation like double quotes.

Heredoc syntax behaves like double-quoted strings, so variables inside are replaced by their values.

❓ Predict Output

intermediate

Output of a nowdoc string with variable inside

What will this PHP code output?

PHP

<?php
$name = "Bob";
$text = <<<'EOD'
Hello, $name!
Welcome to PHP.
EOD;
echo $text;

A

Hello, $name!
Welcome to PHP.

B

Hello, Bob!
Welcome to PHP.

C Syntax error

D Hello, $name! Welcome to PHP.

💡 Hint

Nowdoc strings do not replace variables inside.

Nowdoc syntax treats the content as plain text, so variables are not replaced.

❓ Predict Output

advanced

Behavior of heredoc with complex variable syntax

What is the output of this PHP code?

PHP

<?php
$arr = ['fruit' => 'apple'];
$text = <<<EOD
I like {$arr['fruit']}.
EOD;
echo $text;

A I like .

B I like {$arr['fruit']}.

C Syntax error

D I like apple.

💡 Hint

Heredoc supports complex variable parsing with braces.

Using braces allows PHP to parse complex variables inside heredoc strings correctly.

❓ Predict Output

advanced

Error caused by incorrect heredoc closing identifier

What error does this PHP code produce?

PHP

<?php
$text = <<<EOD
Hello World
Eod;
echo $text;

A Outputs: Hello World

B Parse error: syntax error, unexpected identifier 'Eod'

C Notice: Undefined variable Eod

D Fatal error: Uncaught Error

💡 Hint

Heredoc closing identifier must match exactly, including case.

The closing identifier is case-sensitive and must match the opening one exactly, otherwise a syntax error occurs.

🧠 Conceptual

expert

Difference between heredoc and nowdoc in PHP

Which statement correctly describes the difference between heredoc and nowdoc syntax in PHP?

A Heredoc parses variables and escape sequences; nowdoc treats content as plain text without parsing.

B Nowdoc parses variables and escape sequences; heredoc treats content as plain text without parsing.

C Both heredoc and nowdoc parse variables but differ in escape sequence handling.

D Neither heredoc nor nowdoc parse variables or escape sequences.

💡 Hint

Think about which syntax acts like double quotes and which acts like single quotes.

Heredoc behaves like double-quoted strings, parsing variables and escape sequences. Nowdoc behaves like single-quoted strings, treating content literally.