PHP OOPs 面试题与答案

问题 6. Explain the concept of abstraction.

Abstraction involves hiding the complex implementation details and showing only the necessary features of an object.

问题 7. What is a class in PHP?

A class is a blueprint for creating objects. It defines properties (attributes) and methods that the objects will have.

问题 8. How do you instantiate an object in PHP?

You can instantiate an object using the 'new' keyword followed by the class name. For example: $object = new MyClass();

问题 9. What is a constructor?

A constructor is a special method in a class that is automatically called when an object is created. It is used for initializing object properties.

Example:

class MyClass {
 public function __construct() {
 echo 'Constructor called';
 } 
}

问题 10. Explain the 'static' keyword in PHP.

The 'static' keyword is used to declare static methods and properties. Static methods can be called without creating an instance of the class.

Example:

class MathUtility {
 public static function add($a, $b) {
 return $a + $b;
 } 
}