philiprehberger/php-diff

Diff strings, arrays, and objects with unified, HTML, and structured output

v1.0.3 2026-03-17 20:06 UTC

Requires

• php: ^8.2

Requires (Dev)

• laravel/pint: ^1.0
• phpstan/phpstan: ^1.12|^2.0
• phpunit/phpunit: ^11.0

MIT

• Philip Rehberger

• php
• diff
• compare
• unified-diff
• myers
• html-diff

README

Diff strings, arrays, and objects with unified, HTML, and structured output.

Requirements

Dependency	Version
PHP	^8.2

Installation

composer require philiprehberger/php-diff

Usage

Comparing Strings

use PhilipRehberger\Diff\Diff;

$diff = Diff::strings("hello\nworld", "hello\nphp");

$diff->hasChanges();    // true
$diff->toUnified();     // unified diff string
$diff->toHtml();        // HTML with <ins>/<del> tags
$diff->toArray();       // array of DiffLine objects
$diff->stats();         // DiffStats { added: 1, removed: 1, unchanged: 1 }

Comparing Arrays

use PhilipRehberger\Diff\Diff;

$diff = Diff::arrays(
    ['name' => 'Alice', 'age' => 30, 'city' => 'NYC'],
    ['name' => 'Alice', 'age' => 31, 'country' => 'US'],
);

$diff->hasChanges();  // true
$diff->changes();     // all Change objects
$diff->added();       // entries only in the new array
$diff->removed();     // entries only in the old array
$diff->changed();     // entries with different values

Comparing Objects

use PhilipRehberger\Diff\Diff;

$old = (object) ['name' => 'Alice', 'age' => 30];
$new = (object) ['name' => 'Alice', 'age' => 31];

$diff = Diff::objects($old, $new);

$diff->hasChanges();  // true
$diff->changes();     // [PropertyChange { property: 'age', from: 30, to: 31 }]

API

Diff (Static Entry Point)

Method	Returns	Description
Diff::strings(string $old, string $new)	StringDiff	Compare two strings line by line
Diff::arrays(array $old, array $new)	ArrayDiff	Compare two arrays by key
Diff::objects(object $old, object $new)	ObjectDiff	Compare two objects by property

StringDiff

Method	Returns	Description
toUnified(int $context = 3)	string	Unified diff format
toHtml()	string	HTML with ins/del tags
toArray()	array<DiffLine>	Array of DiffLine value objects
hasChanges()	bool	Whether any differences exist
stats()	DiffStats	Count of added, removed, unchanged lines

ArrayDiff

Method	Returns	Description
changes()	array<Change>	All changes
added()	array<Change>	Only added entries
removed()	array<Change>	Only removed entries
changed()	array<Change>	Only modified entries
hasChanges()	bool	Whether any differences exist

ObjectDiff

Method	Returns	Description
changes()	array<PropertyChange>	All property changes
hasChanges()	bool	Whether any differences exist

Value Objects

• DiffLine — type (added|removed|unchanged), content, lineNumber
• Change — key, old, new, type (added|removed|changed)
• PropertyChange — property, from, to
• DiffStats — added, removed, unchanged

Development

composer install
vendor/bin/phpunit
vendor/bin/pint --test
vendor/bin/phpstan analyse

License

MIT