C数据类型'取值范围为＆QUOT;系统＆QUOT;依赖？ [英] C data types' value range is "system" dependent?

问题描述

我刚开始在C编程PROG。语言和想要得到的数据类型，大小，价值主体连胜。

I just started programming in the C prog. language and want to get the data type-size-value subject straight.

我已经看到了不同的数据类型的几个值范围表（这一个这样的）。

I've seen a few value-range tables of different data types (such as this one).

问题是，我已经学会了和读到这里，有哪些影响每个数据类型的大小不同的参数，我的假设是，值范围应有所不同，以及。

The thing is, I've learned and read here that there are different parameters which influence the size of each data type, and my assumption is that the value-range should vary as well.

例如，如果 1字节= 16位那么我觉得符号字符把持不住0-65535

For example, if 1 byte = 16 bit then I'd think signed char could hold 0-65535.

如何准确是那些表？是他们表现出保证的范围内（但在类型既可以实际持有也较小\\较大值）？

How accurate are those tables? Is the range they show guaranteed (but the types could actually hold also smaller\larger values)?

推荐答案

C语言规范没有定义任何确切的范围内为每个数据类型。它只定义了一个的最小的值特定类型应该能够成立。

The C language specification doesn't define any exact range for each data type. It only defines a minimum value that a particular type should be able to hold.

来到你的问题上的是的表，它不是范围的准确再presentation由C.定义它可能是提交人运行它在特定平台上实现。但它不能总是（并且不应）取为权威源

Coming to your question on that table, it's NOT the accurate representation of ranges for defined by C. It may be true on a particular platform that the author was running it on. But it can't always be (and shouldn't be) taken as the authoritative source.

如果你想知道你的平台上的确切范围，看（或包含）的＆LT; limits.h中> 。或者你可以使用的sizeof 的类型运营商获得的编译器的信息。

If you want to know the exact range on your platform, look at(or include) <limits.h>. Or you can use sizeof operator on the types to get the information from compiler.

如果你想知道的位的再使用 CHAR_BIT 在＆LT的确切数字; limits.h中＆GT ; 。

If you are want to know the exact number of bits then use CHAR_BIT defined in <limits.h>.

例如，可以通过使用发现位在一个int数： CHAR_BIT *的sizeof（INT）

For example, the number of bits in an int can be found using: CHAR_BIT * sizeof(int).

在给定类型相同的方式 T ，可以发现位数： CHAR_BIT *的sizeof（T）。

In same way for a given type T, number of bits can be found: CHAR_BIT * sizeof(T).

另请阅读首先从C-FAQ 这是相当3个或4个问题有关你的问题。

Also read the first 3 or 4 questions from the C-FAQ which are quite relevant to your question.

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