Objective-C:BOOL vs bool

问题描述

我看到了新类型"BOOL(YES，NO).

I saw the "new type" BOOL (YES, NO).

我读到这种类型几乎就像一个字符.

I read that this type is almost like a char.

为了测试我做了:

NSLog(@"Size of BOOL %d", sizeof(BOOL));
NSLog(@"Size of bool %d", sizeof(bool));

很高兴看到两个日志都显示1"(有时在 C++ 中 bool 是一个 int 而它的 sizeof 是 4)

Good to see that both logs display "1" (sometimes in C++ bool is an int and its sizeof is 4)

所以我只是想知道 bool 类型是否有问题?

So I was just wondering if there were some issues with the bool type or something ?

我可以只使用 bool(这似乎有效)而不会降低速度吗?

Can I just use bool (that seems to work) without losing speed?

推荐答案

从objc.h中的定义:

#if (TARGET_OS_IPHONE && __LP64__)  ||  TARGET_OS_WATCH
typedef bool BOOL;
#else
typedef signed char BOOL; 
// BOOL is explicitly signed so @encode(BOOL) == "c" rather than "C" 
// even if -funsigned-char is used.
#endif

#define YES ((BOOL)1)
#define NO  ((BOOL)0)

所以，是的，您可以假设 BOOL 是一个字符.您可以使用 (C99) bool 类型，但 Apple 的所有 Objective-C 框架和大多数 Objective-C/Cocoa 代码都使用 BOOL，因此如果 typedef 只改变使用 BOOL.

So, yes, you can assume that BOOL is a char. You can use the (C99) bool type, but all of Apple's Objective-C frameworks and most Objective-C/Cocoa code uses BOOL, so you'll save yourself headache if the typedef ever changes by just using BOOL.

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