FreeBasic UShort Keyword

last modified June 16, 2025

The FreeBasic UShort keyword represents an unsigned 16-bit integer data type. It can store values from 0 to 65,535. UShort is useful for memory-efficient storage of positive numbers.

Basic Definition

In FreeBasic, UShort is a built-in data type that occupies 2 bytes (16 bits) of memory. It can only contain non-negative integer values in the range 0 to 65,535.

UShort variables are commonly used when working with binary data, file formats, or when memory optimization is important. They prevent negative values while maintaining a compact size.

Declaring UShort Variables

This example shows how to declare and initialize UShort variables.

ushort_declare.bas

Dim age As UShort
Dim population As UShort = 42000
Dim maxValue As UShort = 65535

Print "age: "; age
Print "population: "; population
Print "maxValue: "; maxValue

Here we declare three UShort variables. The first is uninitialized and defaults to 0. The others are explicitly set to values within the valid range. Attempting to assign a negative value would cause an overflow.

UShort Arithmetic Operations

UShort variables can participate in standard arithmetic operations.

ushort_arithmetic.bas

Dim a As UShort = 40000
Dim b As UShort = 25500
Dim result As UShort

result = a + b
Print "Addition: "; result

result = a - b
Print "Subtraction: "; result

result = a * 2
Print "Multiplication: "; result

result = a \ 10
Print "Integer division: "; result

This example demonstrates basic arithmetic with UShort values. Note that adding 40000 and 25500 exceeds the UShort range, causing overflow. FreeBasic will wrap around the value in this case.

UShort in Loop Counters

UShort can be used as loop counters for small iteration ranges.

ushort_loop.bas

Dim i As UShort

For i = 1 To 10
    Print "Iteration: "; i
Next

Dim count As UShort = 0
While count < 5
    Print "While loop count: "; count
    count += 1
Wend

Here we use UShort variables in both For and While loops. This is memory efficient when you know the loop count won't exceed 65,535 iterations. For larger loops, consider using Integer or UInteger instead.

UShort with Arrays

Arrays of UShort values can be useful for memory-efficient storage.

ushort_array.bas

Dim temperatures(7) As UShort
temperatures(0) = 250  ' 25.0°C scaled by 10
temperatures(1) = 255
temperatures(2) = 260

For i As UShort = 0 To 2
    Print "Temperature "; i; ": "; temperatures(i)/10; "°C"
Next

This example creates an array to store temperature readings. We use UShort to store scaled values (25.0°C as 250) for precision while saving memory. Each element takes only 2 bytes instead of 4 bytes for Integer.

UShort with Binary Operations

UShort is often used in bitwise operations due to its fixed 16-bit size.

ushort_binary.bas

Dim flags As UShort = &b1010101010101010
Dim mask As UShort = &b0000000011111111

Print "Original: "; Bin(flags, 16)
Print "AND with mask: "; Bin(flags And mask, 16)
Print "OR with mask: "; Bin(flags Or mask, 16)
Print "XOR with mask: "; Bin(flags Xor mask, 16)
Print "NOT: "; Bin(Not flags, 16)

This demonstrates bitwise operations on UShort values. The binary format shows the exact bit patterns. UShort is ideal for such operations because its size is guaranteed to be 16 bits across platforms.

UShort Type Conversion

FreeBasic can convert between UShort and other numeric types.

ushort_conversion.bas

Dim smallNum As UShort = 32000
Dim largeNum As Integer = 40000

' Implicit conversion from UShort to Integer
Dim result1 As Integer = smallNum

' Explicit conversion from Integer to UShort
Dim result2 As UShort = CUShort(largeNum)

Print "UShort to Integer: "; result1
Print "Integer to UShort: "; result2

This shows type conversion involving UShort. Implicit conversion to larger types is safe, but converting from larger types requires caution. The CUShort function ensures explicit conversion when needed.

UShort with File I/O

UShort is commonly used when reading binary files with 16-bit values.

ushort_file.bas

Dim fileNum As Integer = FreeFile()
Dim values(2) As UShort = {1000, 2000, 3000}

' Write UShort values to binary file
Open "data.bin" For Binary As #fileNum
Put #fileNum, , values
Close #fileNum

' Read UShort values back
Dim readValues(2) As UShort
Open "data.bin" For Binary As #fileNum
Get #fileNum, , readValues
Close #fileNum

For i As Integer = 0 To 2
    Print "Value "; i; ": "; readValues(i)
Next

This example writes and reads an array of UShort values to a binary file. UShort is ideal for binary file operations as it matches common 16-bit formats. The values are stored exactly as their binary representation.

Best Practices

Range Checking: Always validate values fit in 0-65535 range.
Memory Efficiency: Use UShort for large arrays of small numbers.
Binary Data: Prefer UShort when working with 16-bit binary formats.
Type Conversion: Use CUShort for explicit conversions.
Documentation: Comment when UShort is used for specific formats.

This tutorial covered the FreeBasic UShort keyword with practical examples showing its usage in different scenarios.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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