Inheritance is an Object Oriented concept that establishes a relationship between a Parent (/Super) class and a Child (/Sub) class.
The child is said to inherit the members of the parent.
The keyword extends is used in the class signature, as can be seen on line 8 as follows:
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<?php class Person { public $name ; public function speak() { echo "Hi, my name is $this->name, and I'm a person"; } } class Scientist extends Person { public $hair ; public function speak() { echo "Hi, my name is $this->name, and I'm a Scientist!"; echo "I also have long $this->hair hair!!"; } } $julia = new Scientist ; $julia->name = "Julia" ; $julia->hair = "blonde" ; $julia->speak() ; ?> |
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| Hi, my name is Julia, and I'm a Scientist! I also have long blonde hair!! |
The new Scientist class has extended the Person class, and in this case has also overridden the speak() method of the parent.