9.37. Swift construction process

发布时间 :2023-12-08 01:10:05 UTC      

The construction process is a preparation process for using an instance of aclass, structure, or enumerated type. This process involves setting initialvalues for each property in the instance and performing the necessary preparation and initialization tasks for it.

The Swift constructor uses the init() method.

Vs. Objective-C unlike the constructors in Swift, the constructors in Swift do not need to return values, and their main task is to ensure that the new instance is initialized correctly before it is used for the first time.

Class instances can also clean up memory before the class instance is released by defining a destructor (deinitializer).

Principles, Technologies, and Methods of Geographic Information Systems  102

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.