什么是＆QUOT; K＆QUOT;站在可可常量名 [英] What does the "k" stand for in Cocoa constant names

问题描述

可能重复：结果
  <一href=\"http://stackoverflow.com/questions/675816/what-does-the-k-$p$pfix-indicate-in-apples-apis\">What请问'K'preFIX表明苹果的API？结果
  <一href=\"http://stackoverflow.com/questions/1230854/objective-c-why-do-constants-start-with-k\">Objective Ç - 为什么常数以K开头

例如，<一个href=\"http://developer.apple.com/library/mac/#documentation/AudioToolbox/Reference/AudioFormatServicesReference/Reference/reference.html%23//apple_ref/doc/uid/TP40007286-CH5-SW1\"相对=nofollow>结果codeS音频格式服务定义的：

• kAudioFormatUnspecifiedError


• kAudioFormatUnsupportedPropertyError


• 等...

什么是领导ķ立场？我总是假定关键，因为这样的常数常常用作在字典的键，但这些结果codeS是其中常数只是一个返回值，而不是一个例子（尽可能的API的客户端可以确定）的关键。

What does that leading k stand for? I've always assumed key, since such constants are often used as the keys in dictionaries, but those result codes are an example of where the constant is just a return value, not (as far as a client of the API can determine) a key.

推荐答案

我想，它只是代表k'onstant，其中k的使用，因为'C'已经被常用来表示的类的或匈牙利命名法的字符的。

I imagine that it merely stands for 'k'onstant, where 'k' is used because 'c' is already commonly used to indicate class or in Hungarian notation character.

的使用是有历史precedent;使用'K'早袖珍计算器来表示的恒定模式的（其中 = 的反复操作多次最后一次操作），因为'C'用于清除的

The usage has historical precedent; early pocket calculators used 'k' to indicate constant mode (where repeated operation of = repeated the last operation) because 'c' was used for clear.

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