Differences between php this, self and parent

1. this is a pointer to the current object

For example: other functions in the same class can be called with this->function name.

2. Self is a pointer to the current class

Generally, self is used to point to static variables in the class. Also note that using self to call static variables must use:: (field operation symbol)

For example: self::$firstCount; //Use self to call static variables

3. Parent is a pointer to the parent class

Generally we use parent to call the constructor of the parent class

For example: parent::__construct( "PBPHome"); //Use parent to call the constructor of the parent class