int和long在C ++中有什么区别?
纠正我,如果我错了,
int是4个字节,范围从-2,147,483,648到2,147,483,647(2 ^ 31)
长为4个字节,范围从-2,147,483,648到2,147,483,647(2 ^ 31)
C ++有什么区别? 它们可以互换使用吗?
它依赖于实现。
例如,在Windows下它们是相同的,但是例如在Alpha系统上,长度是64位,而int是32位。 本文介绍了可变平台上的英特尔C ++编译器规则。 总结:
OS arch size
Windows IA-32 4 bytes
Windows Intel 64 4 bytes
Windows IA-64 4 bytes
Linux IA-32 4 bytes
Linux Intel 64 8 bytes
Linux IA-64 8 bytes
Mac OS X IA-32 4 bytes
Mac OS X Intel 64 8 bytes
唯一的保证是:
sizeof(char) == 1
sizeof(char) <= sizeof(short) <= sizeof(int) <= sizeof(long) <= sizeof(long long)
// FROM @KTC. The C++ standard also has:
sizeof(signed char) == 1
sizeof(unsigned char) == 1
// NOTE: These size are not specified explicitly in the standard.
// They are implied by the minimum/maximum values that MUST be supported
// for the type. These limits are defined in limits.h
sizeof(short) * CHAR_BIT >= 16
sizeof(int) * CHAR_BIT >= 16
sizeof(long) * CHAR_BIT >= 32
sizeof(long long) * CHAR_BIT >= 64
CHAR_BIT >= 8 // Number of bits in a byte
另见: long
保证至少32位?
编译x64时,int和long之间的差别在0到4个字节之间,具体取决于您使用的编译器。
GCC使用LP64模型,这意味着在64位模式下,整数是32位,但长度是64位。
例如MSVC使用LLP64模型,这意味着即使在64位模式下,int和long也是32位。
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