[c#] How do I convert uint to int in C#?

How do I convert uint to int in C#?

Take note of the checked and unchecked keywords.

It matters if you want the result truncated to the int or an exception raised if the result doesnt fit in signed 32 bits. The default is unchecked.

Convert.ToInt32() takes uint as a value.

Assuming that the value contained in the uint can be represented in an int, then it is as simple as:

int val = (int) uval;

Assuming you want to simply lift the 32bits from one type and dump them as-is into the other type:

uint asUint = unchecked((uint)myInt);
int asInt = unchecked((int)myUint);

The destination type will blindly pick the 32 bits and reinterpret them.

Conversely if you're more interested in keeping the decimal/numerical values within the range of the destination type itself:

uint asUint = checked((uint)myInt);
int asInt = checked((int)myUint);

In this case, you'll get overflow exceptions if:

• casting a negative int (eg: -1) to an uint
• casting a positive uint between 2,147,483,648 and 4,294,967,295 to an int

In our case, we wanted the unchecked solution to preserve the 32bits as-is, so here are some examples:

Examples

int => uint

int....: 0000000000 (00-00-00-00)
asUint.: 0000000000 (00-00-00-00)
------------------------------
int....: 0000000001 (01-00-00-00)
asUint.: 0000000001 (01-00-00-00)
------------------------------
int....: -0000000001 (FF-FF-FF-FF)
asUint.: 4294967295 (FF-FF-FF-FF)
------------------------------
int....: 2147483647 (FF-FF-FF-7F)
asUint.: 2147483647 (FF-FF-FF-7F)
------------------------------
int....: -2147483648 (00-00-00-80)
asUint.: 2147483648 (00-00-00-80)

uint => int

uint...: 0000000000 (00-00-00-00)
asInt..: 0000000000 (00-00-00-00)
------------------------------
uint...: 0000000001 (01-00-00-00)
asInt..: 0000000001 (01-00-00-00)
------------------------------
uint...: 2147483647 (FF-FF-FF-7F)
asInt..: 2147483647 (FF-FF-FF-7F)
------------------------------
uint...: 4294967295 (FF-FF-FF-FF)
asInt..: -0000000001 (FF-FF-FF-FF)
------------------------------

Code

int[] testInts = { 0, 1, -1, int.MaxValue, int.MinValue };
uint[] testUints = { uint.MinValue, 1, uint.MaxValue / 2, uint.MaxValue };

foreach (var Int in testInts)
{
    uint asUint = unchecked((uint)Int);
    Console.WriteLine("int....: {0:D10} ({1})", Int, BitConverter.ToString(BitConverter.GetBytes(Int)));
    Console.WriteLine("asUint.: {0:D10} ({1})", asUint, BitConverter.ToString(BitConverter.GetBytes(asUint)));
    Console.WriteLine(new string('-',30));
}
Console.WriteLine(new string('=', 30));
foreach (var Uint in testUints)
{
    int asInt = unchecked((int)Uint);
    Console.WriteLine("uint...: {0:D10} ({1})", Uint, BitConverter.ToString(BitConverter.GetBytes(Uint)));
    Console.WriteLine("asInt..: {0:D10} ({1})", asInt, BitConverter.ToString(BitConverter.GetBytes(asInt)));
    Console.WriteLine(new string('-', 30));
}  

I would say using tryParse, it'll return 'false' if the uint is to big for an int.
Don't forget that a uint can go much bigger than a int, as long as you going > 0

int intNumber = (int)uintNumber;

Depending on what kind of values you are expecting, you may want to check how big uintNumber is before doing the conversion. An int has a max value of about .5 of a uint.

uint i = 10;
int j = (int)i;

or

int k = Convert.ToInt32(i)