nil and void

Nil, Nil, NULL, and NSNull in Objective C. nilnsnull Kenyo's original statement is: the estimation of IOS development is a headache for Objective-C's memory management mechanism. Accidentally, the program will leak memory, and I am no exception, A

1, nil and null literal meaning is simpler, nil is an object, and null is a value, my understanding is nil is to set the object to NULL, and NULL is to set the basic type to empty, the individual feels a bit like the attribute, the basic type is

I. Brief description1.nil is used to assign values to objects (any object in objective-c is of type ID)2.NULL assigns any pointer, null and nil are not interchangeable3.nil for Class pointer assignment (in OBJECTIVE-C the class is an object and is

Nil is used to assign values to an object (any object in objective-c is of type ID), NULL assigns any pointer, null and nil are not interchangeable, nil is used for class pointer assignment (in OBJECTIVE-C, the class is an object, is an instance of

NIL:A null pointer to a Objective-c object. (#define NIL ((ID) 0))Nil is an object value. NIL:A null pointer to a OBJECTIVE-C class. NULL:A null pointer to anything else. (#define NULL ((void *) 0))Null is a generic pointer (generic pointer). Nsnull:

Nil is used to assign values to an object (any object in objective-c is of type ID), NULL assigns any pointer, null and nil are not interchangeable, nil is used for class pointer assignment (in OBJECTIVE-C, the class is an object, is an instance of

Nil: A null pointer to an Objective-c object.(#define NIL ((ID) 0))Nil represents a Objective-c object with a pointer to an emptyNil: A null pointer to an OBJECTIVE-C class.The first capital of nil and nil is a bit different, nil defines a pointer

This article mainly introduces the iOS in Nil, Nil, NULL, Nsnull detailed information, the need for friends can refer to the OBJC inside a few empty value symbols will almost kill me, these basic things should be clear to the line, in order to

NIL: A null pointer to an object that assigns a null value to the objective C ID object.Nil: A null pointer to a class that represents a null value for the class.NULL: A null pointer to another type (for example, base type, C type) to assign a null

1.nil pointer to an object is empty the definition in objc.h is as follows:#ifndef nil# if __has_feature (cxx_nullptr) # define nil nullptr# else# define nil __darwin_null# endif#endifObject in objective-c for ID typeNSString *name = nil; Nsurl