Convert PHP arrays to JSON format with proper syntax and formatting.
PHP Associative Array:
['name' => 'John', 'age' => 30]
→ {"name": "John", "age": 30}
PHP Indexed Array:
['apple', 'banana', 'orange']
→ ["apple", "banana", "orange"]
Nested Array:
['user' => ['name' => 'John', 'active' => true]]
→ {"user": {"name": "John", "active": true}}
Mixed Array:
[1, 'text', true, null]
→ [1, "text", true, null]