IOS rookie learning

1.NS is the system library.
2.IOS class declaration:
@interface MyObject : NSObject {
    int memberVar1; // entity variable
    id memberVar2;
}

+(return_type) class_method; // class method-

(return_type) instance_method1; // instance Method
-(return_type) instance_method2: (int) p1;
-(return_type) instance_method3: (int) p1 andPar: (int) p2;
@end

//+: Represents a class function, which can be used without an instance. The same as c++
    declaration interface Begin, end end.
3. IOS String:
NSString* myString = @"My String\n";
NSString* anotherString = [NSString stringWithFormat:@"%d %s", 1, @"String"];

// from A C language string creates an Objective-C string
NSString* fromCString = [NSString stringWithCString:"AC string"
encoding:NSASCIIStringEncoding];

@ is a mnemonic,Objects can be created from constant strings using mnemonics.

4. IOS class implementation @implementation
MyObject {
  int memberVar3; //private entity variable
}

+(return_type) class_method {
    .... //method implementation
}
-(return_type) instance_method1 {
     ....
}
-(return_type) instance_method2 : (int) p1 {
    ....
}
-(return_type) instance_method3: (int) p1 andPar: (int) p2 {
    ....
}
@end

implementation starts, end ends.

5. The usage of square brackets [class name Class method] or [object instance method]

[VLPAProxyhelper morePlayList:listDic]VLPAProxyhelper class name morePlayList class method listDic parameter

6.id is an object pointer that can be converted to any data type. Not commonly used