I saw in MSDN documents that the maximum value of Int32
is 2,147,483,647
, hexadecimal 0x7FFFFFFF
.
I think, if it's Int32
it should store 32-bit integer values that finally should be 4,294,967,295
and hexadecimal 0xFFFFFFFF
.
My question is why Int32
stores 31-bit integer values?
It's because it's a signed integer. An unsigned 32-bit integer give you the value you expect.
Check out this MSDN page - http://msdn.microsoft.com/en-us/library/exx3b86w(v=vs.80).aspx
For a more in depth explanation on why this is check out the link in Jackson Popes answer related to Two's Complement number representation.
Also some further reading .
Because one bit is used to store the sign (Int32 can be less than zero).
Int32 and Int64 are both signed so they can handle integer values from -capacity/2 to (capacity/2)-1 (for zero) that is why the max value isn't the one you expected. But you can get what you want by using an unsigned int to have only positive numbers.
You are not considering the negative numbers. Int32
have the sign.
From MSDN: http://msdn.microsoft.com/en-us/library/system.int32.minvalue.aspx The MinValue
is -2,147,483,648
; that is, hexadecimal 0x80000000
.
第一位是符号 - 一个int32被签名,即它可以是正/负(我可能不应该说'先'位!)
In a 2's complement signed n-bit type, the range is from -2 n-1 to 2 n-1 -1 because with n bits you can represent 2 n different values, half of which is used for signed numbers because of the sign bit. The remaining 2 n-1 half is used for non-negative number. Since one is used for 0, there are only 2 n-1 -1 remaining values for positive numbers
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.