1. #import的用途1>, like # include, copies the contents of a file2> can automatically prevent the contents of a file from being copied repeatedly
2. #import <Foundation/NSObjCRuntime.h>declaration of NSLog function in NSObjCRuntime.h
3, the path of the foundation framework header file1> Right-click xcode.app-> display Content2> xcode.app/contents/developer/platforms/iphoneos.platform/ developer/sdks/iphoneos6.0.sdk/system/library/frameworks/foundation.framework
4. main header file1> main header file: The main header file, the name is usually the same as the frame namethe primary header file name for the 2> Foundation framework is Foundation.h3> only need to contain the foundation framework Master header file, you can use the whole framework of things
5, OC under the command line of the operation process1> writing OC source files:. m,. C2> Compilation: Cc-c xxx.m xxx.c3> link: cc xxx.o xxx.o-framework Foundation(only the foundation framework is used to add the -framework Foundation)
4> run:./a.out
01 Basic syntax
