十六进制表示法和有符号整数 [英] Hexadecimal notation and signed integers

问题描述

这是一个后续问题.因此，Java存储在 two-s-complements 中的整数，您可以执行以下操作:

This is a follow up question. So, Java store's integers in two's-complements and you can do the following:

int ALPHA_MASK = 0xff000000;

在C#中，这需要使用无符号整数uint，因为它将其解释为4278190080而不是-16777216.

In C# this requires the use of an unsigned integer, uint, because it interprets this to be 4278190080 instead of -16777216.

我的问题是，如何在c#中以十六进制表示法声明负值，以及整数在内部如何精确表示?这里与Java有什么区别?

My question, how do declare negative values in hexadecimal notation in c#, and how exactly are integers represented internally? What are the differences to Java here?

推荐答案

C#(相反，.NET)也使用两者的补码，但它支持有符号和无符号类型(Java不支持).位掩码更自然地是无符号的东西-为什么一个位应该与所有其他位都不同?

C# (rather, .NET) also uses the two's complement, but it supports both signed and unsigned types (which Java doesn't). A bit mask is more naturally an unsigned thing - why should one bit be different than all the other bits?

在这种情况下，使用未经检查的演员表是安全的:

In this specific case, it is safe to use an unchecked cast:

int ALPHA_MASK = unchecked((int)0xFF000000);

要直接"将该数字表示为带符号的值，请输入

To "directly" represent this number as a signed value, you write

int ALPHA_MASK = -0x1000000; // == -16777216

十六进制与(或不应)与十进制没有任何区别:要表示一个负数，您需要写一个负号，后跟代表绝对值的数字.

Hexadecimal is not (or should not) be any different from decimal: to represent a negative number, you need to write a negative sign, followed by the digits representing the absolute value.

这篇关于十六进制表示法和有符号整数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！