What is the UInt32 datatype in VB.NET?
Can someone inform me about its bit length and the differences between UInt32 and Int32? Is it an integer or floating point number?
It's an unsigned 32 bit integer:
U for unsigned
Int for integer
32 for 32
Or you could just look at the documentation:
Represents a 32-bit unsigned integer.
It's a 32 Bit unsigned integer.
Data types in VB.NET notes the following:
UInt32 - 32 bit unsigned integer
Thus, it is 32 bits long, an integer.
A UInt32 is an unsigned integer of 32 bits.
A 32 bit integer is capable of holding values from -2,147,483,648 to 2,147,483,647.
However, as you have specified an unsigned integer it will only be capable of storing positive values. The range on an unsigned 32 bit integer is from 0 to 4,294,967,295.
Attempts to assign values to an Int or UInt outside of its range will result in an System.OverflowException.
Obviously, both UInt32 and Int32 are integers (not floating point), meaning no decimal portion is permitted or stored.
It may also be interesting to note that Integer and System.Int32 are the same in .NET.
For performance reasons you should always try to use Int32 for 32 bit processors and Int64 for 64 bit processors as loading these types to and from memory will be faster than other options.
Finally, try to avoid use of unsigned integers as they are not CLS compliant. If you need positive only integer that has the upper limit of the UInt32 it is better to use an Int64 instead. Unsigned integers are usually only used for API calls and the like.
Related
hi i am new to obj C and i am assigning a text field value to int variable PaidLeaves as below:
because text field return string value i have to cat it to int value so i use following code:
for example
PaidLeaves = txtPaidLeaves.text.intValue;
and
PaidLeaves = txtPaidLeaves.text.integerValue;
above i am assigning a text field value to int value
and both works but what is difference between two expression
please tell me
thank you
intValue returns an int number.
integerValue returns a NSInteger number.
The difference between them is their number of bits, or in easier terms, the range of values that they can store. Has said in an answer of a different question:
int is always 32-bits.
long long is always 64-bits.
NSInteger and long are always pointer-sized. That means they're
32-bits on 32-bit systems, and 64 bits on 64-bit systems.
Reference: https://stackoverflow.com/a/4445467/4370893
Consider that Apple has only made 64 bit systems since Mac OS X 10.7 (Lion), which was released in 2011, so I'm gonna refer to NSInteger has a 64 bit long integer.
So what that means?
The first bit of a signed integer number, like NSInteger and int, is used to define if it's a positive or a negative number. The conclusion is that a signed integer number goes from -2^(number of bits-1) to 2^(number of bits-1)-1, so...
int: - 2,147,483,648 (- 2^31) to 2,147,483,647 (2^31-1)
NSInteger: - 9,223,372,036,854,775,808 (- 2^63) to 9,223,372,036,854,775,807 (2^63-1)
Im looking for a list of all the scalar data types in Objective C, complete with their ranges (max/min values etc).
Sorry for the simple question, Im just really struggling to find anything like this.
int An integer value between +/– 2,147,483,647.
unsigned int An integer value between 0 and 4,294,967,296.
float A floating point value between +/– 16,777,216.
double A floating point value between +/– 2,147,483,647.
long An integer value varying in size from 32 bit to 64 bit depending on architecture.
long long A 64-bit integer.
char A single character. Technically it’s represented as an int.
BOOL A boolean value, can be either YES or NO.
NSInteger When compiling for 32-bit architecture, same as an int, when compiling for 64-bit architecture,+/– 4,294,967,296.
NSUInteger When compiling for 32-bit architecture, same as an unsigned int, when compiling for 64-bit architecture, value between 0 and 2^64
Source.
char : A character 1 byte
int :An integer — a whole number 4 bytes
float : Single precision floating point number 4 bytes
Double : Double precision floating point number 8 bytes
short : A short integer 2 bytes
long : A double short 4 bytes
long long : A double long 8 bytes
BOOL : Boolean (signed char) 1 byte
For more on sizes check this post
Integer types are signed 2's complement or unsigned and the standard C variations are provided (char, short, int, long, long long and unsigned variants of these, see C types on Wikipedia), sizes may vary dependent on 32-bit & 64-bit environments - see 64-bit computing.
BOOL is an Objective-C special and is defined as signed char, while it can take any value a signed char can the constants NO and YES are defined for use. The C9X type _Bool(aka bool) is also provided.
float & double are IEEE 32-bit & 64-bit floating point - see Wikipedia for ranges.
Standard macro contants are provided for the minimum and maximum of all the types, e.g. INT_MAX for int - again see C types on Wikipedia for these.
Related:
Is it safe to assume an int will
always be 32 bits in C#?
The linked question asks whether it is "safe to assume that an int will always be 32 bits in C#". The accepted answer states that "the C# specification rigidly defines that int is an alias for System.Int32 with exactly 32 bits".
My question is this: does this hold true for VB.Net's Integer? Is it safe to assume that Integer will always be an alias for int32?
Yes.
The Integer type will never change.
The spec (7.3 Primitive Types) says:
The integral value types Byte (1-byte unsigned integer), Short (2-byte signed integer), Integer (4-byte signed integer), and Long (8-byte signed integer). These types map to System.Byte, System.Int16, System.Int32, and System.Int64, respectively. The default value of an integral type is equivalent to the literal 0.
VB.Net doesn't have an "int", it has an "Integer" type. The Integer type is an alias for System.Int32. So no, this will not change.
How can I implement a two's complement in VB.NET using unsigned integer types such as Byte, UShort, UInteger and ULong? Can I cast a UInteger to an Integer?
No, you can't cast. That will result in an overflow exception for large values.
You can, however, do this:
intValue = BitConverter.ToInt32(BitConverter.GetBytes(uintValue), 0)
But what stops you from doing the math with the unsigned values without casting them to something? It just works.
I need to a variable which holds a 24 bits value, what should I use ?
Also, do you know a list of all available types in Objc?
Thanks a lot.
You could use an int. It will hold 24 bits. (32, actually)
Objective-C has exactly the same types as plain C. All object references and the id type are technically pointers.
The size of integer datatypes (char … long long) is not defined but their relation and minimum size is.
The smallest integer data type guaranteed to hold 24bit is long int which must be at least 32bit.
int may be 16bit on some systems.
3 chars will be at least 24bit since a char must have 8bit or more.
An array of 3 unsigned chars will be 24 bits (on most systems).