Beginner LevelPHP 8+
What is the difference between var_dump(), print_r(), and var_export() for variable debugging?
❓ Interview Prompt: Compare variable inspection functions regarding data types, string output return values, and executable PHP code exports.
PHP provides three primary functions for inspecting variable structures during debugging:
1. 'var_dump($var)':
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Outputs detailed structural info including data types ('string(5)', 'int(42)') and array/string lengths.
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Does not return a string value directly (outputs to buffer).
2. 'print_r($var, $return)':
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Prints a clean, human-readable structural representation without explicit data types.
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Passing 'true' as 2nd parameter returns the output as a string instead of echoing it.
3. 'var_export($var, $return)':
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Outputs a representation formatted as valid, executable PHP code syntax! Ideal for generating static configuration code files.
Code Implementation Example
php
<?php
$data = ['name' => 'Alice', 'active' => true, 'count' => 5];
// 1. var_dump shows explicit data types and lengths
var_dump($data);
// Outputs: array(3) { ["name"]=> string(5) "Alice" ["active"]=> bool(true) ... }
// 2. print_r returns clean string when 2nd param is true
$readable = print_r($data, true);
// 3. var_export returns valid PHP array code syntax!
$phpCode = var_export($data, true);
// Outputs: array ('name' => 'Alice', 'active' => true, 'count' => 5)💡Comparing var_dump, print_r, and var_export variable inspection outputs.
🎯 Interview Key Takeaway
var_dump shows data types and lengths; print_r gives human-readable structure; var_export outputs valid executable PHP code syntax.
#var_dump#print_r#var_export#Debugging#Beginner
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