如果你传递一个int在C字节参数会发生什么？ [英] What happens if you pass an int to a byte parameter in C?

问题描述

如何C / C ++的协议，如果你传递一个int作为参数成发生在一个字节（一个字符）的方法？是否INT被截断？还是其他什么东西？

How does C/C++ deal if you pass an int as a parameter into a method that takes in a byte (a char)? Does the int get truncated? Or something else?

例如：

void method1()
{
    int i = //some int;
    method2(i);
}

void method2(byte b)
{
     //Do something
}

如何整型得到投到一个字节（一个字符）？它是否会被截断？

How does the int get "cast" to a byte (a char)? Does it get truncated?

推荐答案

刚截断，位模式（字节一般无符号的字符，但是，你必须检查）

Just truncated AS bit pattern (byte is in general unsigned char, however, you have to check)

INT I = -1;

int i = -1;

变为

字节B = 255;当字节= unsigned char型

byte b = 255; when byte = unsigned char

字节B = -1;当字节=符号字符

byte b = -1; when byte = signed char

I = 0; B = 0;

i = 0; b = 0;

我= 1024; B = 0;

i = 1024; b = 0;

我= 1040; B = 16;

i = 1040; b = 16;

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