Runtime----IOS

What is 1.runtime?
Runtime is a set of underlying C-language APIs (including C-language data types, C-language functions)

In fact, we write the OC code at the bottom is based on runtime, in fact, the final turn into the runtime code

For example: [Recevier message] actually converted to Objc_msgsend (Recevier,selector)

The role of 2.runtime

* A method that dynamically produces a member variable of a class

* Can dynamically modify a class one member variable one method

* A method that can dynamically delete a member variable of a class

Runtime----IOS