在 Objective-c 中，比较 2 个 BOOL 值的安全和好方法? [英] In Objective-c, safe and good way to compare 2 BOOL values?

问题描述

我想比较 Objective-c 中的 2 个 BOOL 值.

I want to compare 2 BOOL values in objective-c.

我发现以下代码中的 (3)-(6) 有效.
(1)-(2) 不起作用，因为 BOOL 只是 signed char.

I found out that (3)-(6) of the following code works.
(1)-(2) doesn't work because BOOL is just signed char.

(3) 有效且可读性强，但我认为 bool 不是 Objective-c.
在objective-c代码中使用bool好不好?

(3) works and is very readable but I think bool isn't objective-c.
Using bool in objective-c code is good?

在 Objective-c 中比较 2 个 BOOL 值的安全和好方法是什么?
还有其他更好的比较方法吗?

Which is the safe and good way to compare 2 BOOL values in objective-c?
Are there other better ways to compare?

BOOL b = YES;
BOOL c = 2;

NSLog(@"(1) %d", b == c); // not work
NSLog(@"(2) %d", (BOOL)b == (BOOL)c); // not work
NSLog(@"(3) %d", (bool)b == (bool)c);
NSLog(@"(4) %d", !b == !c);
NSLog(@"(5) %d", !!b == !!c);
NSLog(@"(6) %d", (b != 0) == (c != 0));

结果:

(1) 0
(2) 0
(3) 1
(4) 1
(5) 1
(6) 1

推荐答案

在 Objective-C 中使用 bool 是完全有效的，因为它是 C99 标准的一部分(第 7.16 节).在我看来，这也是处理布尔类型安全比较的最佳方式.

It's perfectly valid to use bool in Objective-C as it's part of the C99 standard (§7.16). In my opinion it's also the best way to handle safe comparisons of boolean types.

不到处使用 bool 的唯一原因是 BOOL 在 Objective-C 和框架中无处不在.

The only reason not to use bool everywhere is that BOOL is omnipresent in Objective-C and the frameworks.

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