是否有关于NSLog()内可以使用的所有代码的概述? [英] Is there an overview of all codes that can be used inside NSLog()?

问题描述

即％@表示字符串，％f表示双打...我不知道这些占位符的含义，但是如果能找到如何打印布尔值和其他值的列表，那就太好了.

i.e. %@ for strings, %f for doubles... I don't know the word for these placeholders but it would be great to have list for how to print booleans and other values.

推荐答案

由于 NSLog 将 NSString 作为其参数，因此它使用 NSString 格式说明符.这实际上与常见的 printf 说明符相同.另外，％@ 指示符不限于 NSString 对象，而是用于任何Objective-C对象.基本的 NSObject 类提供了由对象的类及其地址组成的对象的一般描述，但是许多对象会提供特定于其类型的信息，例如集合类( NSArray ， NSDictionary )，它将提供格式正确的内容转储.您可以通过覆盖 -description 为创建的自己的对象提供此功能(有关更多信息，包括本地化功能，请参阅文档).

Since NSLog takes a NSString as its argument, it uses the NSString format specifiers. This is virtually identical to the common printf specifiers. Also, the %@ specifier is not limited to NSString objects, but is for any Objective-C objects. The base NSObject class provides a generic description of the object consisting of its class and its address, but many objects will supply information specific to their type, such as the collection classes (NSArray, NSDictionary) which will supply nicely formated dump of their contents. You can provide this for your own objects that you create by overriding -description (see the documentation for more info, including localization capability).

另请参见: NSString格式说明符

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