 Data types: uint8, uint16, uint32, uint64

Represents an unsigned integer number stored with 8, 16, 32 or 64 bit.

Type syntax

uint8

uint16

uint32

uint64

Literal syntax

decimal‑literal

0xhex‑decimal‑literal

Discussion

The number of bits determines directly the range for the respective values:

Number of bits

Min. value

Max. value

8 bit

0

255

16 bit

0

65535

32 bit

0

4294967295

64 bit

0

2^64 - 1

The unsigned integer numbers may be expressed in either decimal or hexadecimal notation. A number in hexadecimal notation begins with the prefix 0x. The literals can be used within expressions wherever an uint8, uint16, uint32 or uint64 operand is expected. The type names, in turn, are designated to be used in declarations of data members. For example:

var uint32 options = 0xF7700088; var uint16 voltage = 6000;

64-bit restrictions on WebGL (JavaScript) target

The 64-bit support depends on the features available in the particular target system. This is especially problematic when developing a GUI application for the WebGL target system. In this case the underlying JavaScript language does not support the storage of real 64-bit integer values nor it is able to perform real-64 bit arithmetic operations. In fact, JavaScript manages numbers as 64-bit floating point entities with maximal 53-bit intended to store the number (mantissa). As soon as an integer value exceeds 53-bit the precision will decline. This should be taken in account when you perform arithmetic operations with the supposed 64-bit numbers.

Even more restrictive is the case if you intend to perform bitwise operations on 64-bit operands. JavaScript reduces in such cases the operands to 32-bit causing the results of the operation to be not predictable. Therefore, when targeting WebGL you should be careful and avoid the usage of more than 53-bit in uint64 operands for arithmetic operations and even 32-bit for bitwise operations.

When generating code for WebGL target Embedded Wizard verifies uint64 operands and reports warnings if an operation is suspect and not guaranteed to produce correct results. For example, the increment operator ++ may fail if the operand it is applied on would contain a large number. Embedded Wizard reports in such case a warning like shown below: Arithmetic operations

You can combine an unsigned integer operand with other operands to arithmetic expressions. The following table provides an overview of the possible operations:

Operator

Short description

+

-

Subtraction

*

Multiplication

/

Division

%

Modulo division

Bitwise operations

You can apply bitwise operations on unsigned integer operands. The operations are applied on all 8, 16, 32 or 64 bits of the operand. The following table provides an overview of the possible operations:

Operator

Short description

~

Bitwise NOT

&

AND

|

OR

^

XOR

>>

Right shift

<<

Left shift

Comparison operations

You can compare two unsigned integer operands in order to test whether these are equal or not. The following table provides an overview of the possible operations:

Operator

Short description

==

Equality

!=

Inequality

<

Less than

>

Greater than

<=

Less than or equal

>=

Greater than or equal

Type conversions

Chora reacts sensitive when mixing operands of different data types within an operation. To avoid compiler warnings or even errors you can convert the affected operands explicitly by using following conversion operations:

Conversion operations with unsigned integers

Conversion between signed and unsigned integers.

Conversion to or from a floating-point value.

Conversion to or from an enumeration value.

Conversion to or from a set value.

Conversion to or from a char value.

Formatting a string from an unsigned integer number.

Parsing a string as an unsigned integer number.