核心数据中的NSNumber（整数16，32，64）应该用于保持NSUInteger [英] What NSNumber (Integer 16, 32, 64) in core data should I use to keep NSUInteger

问题描述

我想将NSUInteger保存为我的核心数据，我不知道应该使用哪种类型（整数16,32,64）来满足所需的空间。

从我的理解

 整数16可以有最小值-32,768到32,767 
整数32可以有最小值-2,147,483,648到2,147,483,647 
整数64可以有最小值 - 非常大到非常大
  

，NSUInteger是unsiged long的类型def，等于unsigned int（ objective-c中的类型在iPhone上）

所以如果我将NSUInteger转换为NSNumber与numberWithUnsignedInteger：并保存为NSNumber（整数32）我可以安全地检索我的数据 是否需要 NSUInteger 的整个范围 / code>？在iOS上是一个无符号的32位值，这可能会非常大。它会找到一个有符号的64位。

但你可能不需要那么多的精度。 uint32_t 的最大值为 UINT32_MAX ，为4,294,967,295（40亿）。如果您每秒增加一次，则需要超过136年才能达到该值。您的用户的iPhone不会在那时...：）

I want to keep NSUInteger into my core data and I don't know which type should I use (integer 16, 32, 64) to suit the space needed.

From my understanding

Integer 16 can have minimum value of -32,768 to 32,767
Integer 32 can have minimum value of -2,147,483,648 to 2,147,483,647
Integer 64 can have minimum value of -very large to very large

and NSUInteger is type def of unsiged long which equal to unsigned int (Types in objective-c on iPhone)

so If I convert my NSUInteger to NSNumber with numberWithUnsignedInteger: and save it as NSNumber(Integer 32) I could retrieve my data back safely right ?

解决方案

Do you really need the entire range of an NSUInteger? On iOS that's an unsigned 32 bit value, which can get very large. It will find into a signed 64 bit.

But you probably don't need that much precision anyway. The maximum for a uint32_t is UINT32_MAX which is 4,294,967,295 (4 billion). If you increment once a second, it'll take you more than 136 years to reach that value. Your user's iPhone won't be around by then... :)

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