3.3 Reference types
Unityengine.object class
Unityengine.component class
Because the build itself cannot be attached directly to the game object, the component can only be coded by script, in effect adding the script of the corresponding component to the game object.
A generic version of the Getcomponents method is often recommended from a performance standpoint. A method like getcomponents is best to save a reference to a target object on the first call, rather than calling the method repeatedly to get a reference to the target object.
Unityengine.monobehaviour class
The Monobehaviour class inherits from the Unityengine.behaviour class.
The Monobehaviour class is the base class for all Unity3d scripts. When you want to use the C # language to complete a new script, you must explicitly inherit the Monobehaviour class (that is, the type declared in the new script must be specified to inherit from the Monobehaviour Class).
Any type that inherits from the Monobehaviour class or the Monobehaviour class itself cannot be instantiated with the new keyword.
You need to create an object that inherits the type of the Monobehaviour class, P81
The characteristics and execution order of event functions P81-p90
3.4.1 Vector2 Vector3 Vector4
Point Multiply fork Multiply p92-p94
3.5 Box and unboxing P95