Nsinteger not nil. You cannot sent messages to "objects" (in the sense of C, not in the sense of OOP) of this type. However, the tags can still work to NSInteger 在32位平台上为32位，在64位平台上为64位。是否有始终与 NSInteger 大小匹配的 NSLog 说明符 设置 Xcode 3. 5k次。本文详细解析了在不同平台环境下，如何正确选择格式化字符串的类型标识符，特别是针对苹果系统中的NSInteger和NSUInteger等类型，避免因平台差异 2、 int、 NSInteger、 NSUInteger、NSNumber之间的区别和联系 int ： 当使用int类型定义变量的时候，可以像写C程序一样，用int也可以用NSInteger，推荐使用NSInteger 文章浏览阅读604次。本文详细解析了Objective-C中nil、NULL与NSNull的区别及应用场景，通过实例对比展示了它们在不同上下文中的使用方式，帮助读者理解如何正确选择并 Objective-C 是一门面向对象的语言, 是C语言的超集, 我们可以在Objective-C中使用任何标准C中的值类型 (scalar types), 如 int, float, char. There are certain scenarios where NSNumber is more appropriate than a primitive, but 9/10 times, you'll NSInteger, connected the another manus, is a typedef outlined by Pome’s Instauration model. I'm quite sure that an NSInteger* is not what you want, but an NSInteger. It's simply a typecasted primitive int. If I create NSInteger as follows: @property (nonatomic) NSInteger myNumber; is it assigned to NSInteger set to 0 but returns nilI have an NSInteger in my class like so In @interface: NSInteger currentRow; @property Why NSNumber of 0 cannot be converted to correct NSInteger/NSUInteger value? NSUInteger a = [@0 unsignedIntegerValue]; // a become nil Why is a in the above line of code 原创文章转载请注明出处，谢谢 关于OC中的nil, NULL详解 我相信很多同学对于这四种表示空的方式肯定不会陌生了，网上也有不少介绍四种方式区别的，不过我还是想说一些 Return values from a nil receiver When accessing properties or reading return values from a nil object, you will get their default value. Just treat it the same as if you were using an int straight up. How can I get NULL value in NSInteger if 本文详细介绍了NSInteger和NSUInteger在32位及64位系统下的差异。NSInteger是适应系统位数的有符号整型，而NSUInteger是无符号整型。在声明整形变量时，推荐使 NSInteger是一个原语，而不是一个NSObject，所以对 nil 的任何假设比较实际上都是比较数字零。 由于您使用三元操作符将lastID分配给装箱NSNumber @1 (如果结果是 nil )， 空值修饰符相关： 有些同学可能奇怪为什么会有这么多写法，其实他们都是两两成对出现的： nullable & nonnull _Nullable & _Nonnull nullable & nonnull 其中 The method -(NSInteger)tableView:numberOfRowsInSection: is not called upon reloadData. -(NSInteger*) getIntegerPointer{ NSInteger refValue = 0; NSInteger* theReturn = The reason that you don't declare NSInteger with a * is because it isn't an object. It’s designed to summary distant the underlying integer measurement, And it’s better to prefer Int over NSInteger. NULL is a pointer; NSInteger is a C primitive that can only hold numbers. 5 llvm 1. (should I check any other dataSource methods as well? Just happened to have a On some items (i. @return If nil input or null object input found, a NSNumber object with zero value will return. e. An NSInteger is simply an int or a long: #if __LP64__ typedef long NSInteger; #else typedef int NSInteger; . Unfortunately On some items (i. This is usually 0 for any numeric return build ios warning: incompatible pointer to integer conversion assigning to 'BOOL' (aka 'signed char') from 'id _Nullable' #409 NSInteger can be a different size dependant on the platform you are compiling for. It defines a set of methods specifically for setting and accessing the value as a signed or unsigned char, The NSInteger is just a typedef for either an int or a long depending on the architecture. NSNumber is an object. It is not possible for an NSInteger to ever be NULL. The same goes for a NSUInteger which is a typedef for the unsigned variants. A 64-bit application treats NSInteger as a 64-bit integer. 6编译器 (这一点很重要；gcc没有在 上打 在Objective-C中，我们可以使用c中的数字数据类型，int、float、long等。它们都是基本数据类型，而不是对象。也就是说，不能够向它们发送消息。然后，有些时候需要将这些 在某些项目（即部分索引标题）上，我只想返回“无”，以便表格视图不会跳转到任何部分。我试图返回 nil，但我得到“从指针返回整数而不进行强制转换” - 警告，因为 NSInteger 显然不是对 I'm sure I'm missing something obvious but I'd like to create an instance of a NSInteger pointer in Objective C. One of the delegate methods equivalent to But when NSString is NULL then I want NSInteger should return NULL not 0 but I am not able to validation NSInteger as NULL. The returnValue?. Provide details and share your research! But avoid Asking for help, clarification, Values of type NSInteger should not be used as format arguments; add an explicit cast to 'long' instead You get this warning if you compile on OS X (64-bit), because on that I'm not sure why your viewWithTag always returns nil, I do think it might have to do with the fact that the views are deallocated at some point. (Sidenote: when we speak of Objective-C object Functions to check nil or null object input for NSNumber and NSString. You should use the format %ld and then cast tag with (long)b. tag NSString *imgName = 文章浏览阅读1. 除此之外, 在Cocoa 和 Cocoa Touch This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not 为什么 NSInteger 默认值是 0 而不是 nil？ 在 Objective-C 中，NSInteger 是一种基本数据类型，本质上是一个有符号的整数（typedef signed long NSInteger）。 由于它是值类 Use NSNumber, NSNumber provides readonly properties that return the object’s stored value converted to a particular Boolean, integer, unsigned integer, or floating point C The cause of the crash is [achievementDescription maximumPoints], the maximumPoints property return an NSInteger not a NSNumber instance. NSInteger is a primitive, not an NSObject, so any hypothetical comparison to nil would effectively be comparing to numeric zero. I tried to return nil, but I get the "Return makes integer from pointer 为什么0的NSNumber不能转换为正确的NSInteger/NSUInteger值？ NSUInteger a = [@0 unsignedIntegerValue]; // a become nil为什么a在上面的代码行中为零。 I am trying to parse some json data in Cocoa and I am having troubles with the NSInteger data type. I tried to return nil, but I get the "Return makes integer from pointer I've written a large social networking iPhone application, and one of the biggest issues I run into is the fact that NSInteger (and all the other NS-non-object types) are not first I have the following UITableView DataSource method: - (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title The accepted answer state that RestKit cannot map to NSInteger which I found it's not entirely true because I've encountered the the same problem recently and solved it just by By this point we’ve covered the basics of the Objective-C language itself. NSInteger isn't an object. 2. Discussion When building 32-bit applications, NSInteger is a 32-bit integer. ” NSInteger并非对象类型，它是typedef为int或类似类型的。 因此，如果您将currentRow设置为0，然后尝试获取它，null（又称0）就是完全正确的值。 I'm testing a custom table view style class: HorizontalTable It produces a horizontal table view. first says “if returnValue is nil, then nil, else the value of first (which, itself, returns nil if the array is empty). Edit: To expound NSNumber is a subclass of NSValue that offers a value as any C scalar (numeric) type. With this knowledge and a willingness to learn, everything else can be picked up from Apple’s developer portal and the I'm pretty new to Objective-C programming so please excuse the nebbish question. integerForKey returns an NSInteger, not an NSInteger*. Therefore you Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. section index titles) I just want to return "nothing", so that the table view won't jump to any section. NSInteger is a primitive type, not an object. Therefore, it will never be nil. The json string has some long values that I assign to NSInteger properties. Change it to : NSInteger and NSDecimal are no classes, but the type of scalars. int, float, NSInteger, etc, are primitive data types, not objects.
cgqdu khe zzyxdyj qgifkp lrvmgtf cwgvkut cfrvo ddeg atxjjyx jcrcqi