uCalc API Version: 5.7.0-preview.1 Released: 7/30/2026

Warning

uCalc API Preview Release Notice:This preview documentation describes the intended behavior of the API. It is not fully accurate or complete.The current preview build contains incomplete features, unoptimized performance, and is subject to breaking changes.Use of the preview version in your production code is not recommended.

ValueAddr()

Method

Product: 

Fast Math Parser

Class: 

Item

Returns the memory address of an item's value, enabling low-level interoperability and direct memory manipulation.

Syntax

ValueAddr()

Parameters

[None]

Return

IntPtr

A pointer to the item's underlying value. The exact type is platform-dependent (e.g., IntPtr in .NET).

Remarks

The ValueAddr method provides a way to get a direct pointer to the memory location where a uCalc item's value is stored. This is an advanced feature primarily used for high-performance scenarios, such as binding uCalc variables to variables in the host application or modifying values by reference within a callback.

Core Use Cases

  • Host Application Binding: Link a uCalc variable directly to a native variable in C++, C#, or VB.
  • Passing by Reference: Obtain a pointer to pass to a callback function that needs to modify the original value.
  • Low-Level Introspection: Use with methods like ValueAt to dereference the pointer and read the value.

ValueAddr vs. ValuePtr: The Critical Distinction

It is essential to understand the difference between ValueAddr() and ValuePtr(), especially when working with pointer-type variables. Failing to do so can lead to subtle bugs or memory access errors.

MethodDescriptionExample Scenario
ValueAddr()Returns the memory address OF the item itself.If you have a variable x, x.ValueAddr() gives you the location where the value of x is stored.
ValuePtr()Returns the memory address STORED IN the item.If you have a variable p As Int Ptr, p.ValuePtr() gives you the address that p is pointing to, not the address of p itself.

In short: ValueAddr is for getting the address of any variable, while ValuePtr is for getting the address held by a pointer variable.

⚖️ Comparative Analysis

  • vs. C++ (& operator): ValueAddr() is conceptually similar to C++'s address-of operator (&). int x = 10; int* p = &x; is analogous to var x = uc.DefineVariable("x=10"); var p = x.ValueAddr();.

  • vs. C# (unsafe context): In C#, getting the address of a managed variable requires an unsafe block and fixed pointers. uCalc provides a safer, managed way to achieve similar low-level memory access without leaving the managed environment, abstracting away the complexities of garbage collection and memory pinning.

Examples

Pointer value with ValueAt

ID: 82

See: ValueAddr(), ValueAt 
				
					using uCalcSoftware;

var uc = new uCalc();
uc.Format("Result = 'Answer: <' + Result + '>'");

var Dbl = uc.DefineVariable("MyDouble = 123.456");

Console.WriteLine(uc.ValueAt(Dbl.ValueAddr(), "Double"));
Console.WriteLine(uc.ValueAt(Dbl.ValueAddr(), BuiltInType.Float_Double));
Console.WriteLine(uc.ValueAt(Dbl.ValueAddr(), BuiltInType.Float_Double, true));


				
			
123.456
123.456
Answer: <123.456>
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uc.Format("Result = 'Answer: <' + Result + '>'");

   auto Dbl = uc.DefineVariable("MyDouble = 123.456");

   cout << uc.ValueAt(Dbl.ValueAddr(), "Double") << endl;
   cout << uc.ValueAt(Dbl.ValueAddr(), BuiltInType::Float_Double) << endl;
   cout << uc.ValueAt(Dbl.ValueAddr(), BuiltInType::Float_Double, true) << endl;


}
				
			
123.456
123.456
Answer: <123.456>
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      uc.Format("Result = 'Answer: <' + Result + '>'")
      
      Dim Dbl = uc.DefineVariable("MyDouble = 123.456")
      
      Console.WriteLine(uc.ValueAt(Dbl.ValueAddr(), "Double"))
      Console.WriteLine(uc.ValueAt(Dbl.ValueAddr(), BuiltInType.Float_Double))
      Console.WriteLine(uc.ValueAt(Dbl.ValueAddr(), BuiltInType.Float_Double, true))
      
      
   End Sub
End Module
				
			
123.456
123.456
Answer: <123.456>
Explore 600+ other examples
Returning a pointer with ReturnPtr

ID: 86

See: ArgItem, ReturnPtr, ValueAddr() 
				
					using uCalcSoftware;

var uc = new uCalc();

static void GetAddressOf(uCalc.Callback cb) {
   cb.ReturnPtr(cb.ArgItem(1).ValueAddr());
}


// This example is for sake of illustration
// There is already a built-in AddressOf() function

uc.DefineFunction("GetAddressOf(ByHandle Variable As AnyType) As SameTypeAs:0 Ptr", GetAddressOf);

uc.DefineVariable("MyVariable = 123.456");
uc.DefineVariable("MyStr = 'Hello world!'");

Console.WriteLine(uc.EvalStr("ValueAt(GetAddressOf(MyVariable))"));
Console.WriteLine(uc.EvalStr("ValueAt(GetAddressOf(MyStr))"));
				
			
123.456
Hello world!
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

void ucalc_call GetAddressOf(uCalcBase::Callback cb) {
   cb.ReturnPtr(cb.ArgItem(1).ValueAddr());
}
int main() {
   uCalc uc;

   // This example is for sake of illustration
   // There is already a built-in AddressOf() function

   uc.DefineFunction("GetAddressOf(ByHandle Variable As AnyType) As SameTypeAs:0 Ptr", GetAddressOf);

   uc.DefineVariable("MyVariable = 123.456");
   uc.DefineVariable("MyStr = 'Hello world!'");

   cout << uc.EvalStr("ValueAt(GetAddressOf(MyVariable))") << endl;
   cout << uc.EvalStr("ValueAt(GetAddressOf(MyStr))") << endl;
}
				
			
123.456
Hello world!
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   
   Public Sub GetAddressOf(ByVal cb As uCalc.Callback)
      cb.ReturnPtr(cb.ArgItem(1).ValueAddr())
   End Sub
   Public Sub Main()
      Dim uc As New uCalc()
      
      '// This example is for sake of illustration
      '// There is already a built-in AddressOf() function
      
      uc.DefineFunction("GetAddressOf(ByHandle Variable As AnyType) As SameTypeAs:0 Ptr", AddressOf GetAddressOf)
      
      uc.DefineVariable("MyVariable = 123.456")
      uc.DefineVariable("MyStr = 'Hello world!'")
      
      Console.WriteLine(uc.EvalStr("ValueAt(GetAddressOf(MyVariable))"))
      Console.WriteLine(uc.EvalStr("ValueAt(GetAddressOf(MyStr))"))
   End Sub
End Module
				
			
123.456
Hello world!
Explore 600+ other examples
DefineVariable; using pointers

ID: 18

See: DefineVariable, SetScalar, ValueAddr(), ValuePtr(POINTER) 
				
					using uCalcSoftware;

var uc = new uCalc();
var Int8Var = uc.DefineVariable("x As Int8 = -1");
var Int16Var = uc.DefineVariable("y As Int16 = -1");
var StrVar = uc.DefineVariable("MyStr = 'Hello there'");
Console.WriteLine(uc.EvalStr("x"));
Console.WriteLine(uc.EvalStr("y"));
Console.WriteLine(uc.EvalStr("MyStr"));

var xPtr = uc.DefineVariable("xPtr As Pointer"); // General pointer
var yPtr = uc.DefineVariable("yPtr As Int16u Ptr"); // pointer specific to unsigned Int16
var yPtrB = uc.DefineVariable("yPtrB As Int16 Ptr = AddressOf(y)"); // Using AddressOf
var StrPtr = uc.DefineVariable("StrPtr As String Ptr");
xPtr.ValuePtr(Int8Var.ValueAddr()); // Sets the pointer address
yPtr.ValuePtr(Int16Var.ValueAddr()); // Note: address of signed Int16 going to an unsigned Ptr
StrPtr.ValuePtr(StrVar.ValueAddr());

// Note: for the ints we are now returning unsigned values; so -1 turns into positive numbers
Console.WriteLine(uc.EvalStr("ValueAt(Int8u, xPtr)")); // Type required because it's defined as generar pointer
Console.WriteLine(uc.EvalStr("ValueAt(yPtr)")); // Type name not needed because it's defined as Int16u Ptr
Console.WriteLine(uc.EvalStr("ValueAt(yPtrB)"));
Console.WriteLine(uc.EvalStr("ValueAt(StrPtr)"));

// Iterate through uc.ItemOf(ItemIs.DataType, n).Name()
// to see data type names you can use with ValueAt

var OtherInt = uc.DefineVariable("OtherInt As Int16 = 1234");
uc.DataTypeOf(BuiltInType.Integer_16).SetScalar(Int16Var.ValueAddr(), OtherInt.ValueAddr());

Console.WriteLine(uc.EvalStr("OtherInt"));
Console.WriteLine(uc.EvalStr("ValueAt(yPtrB)"));





				
			
-1
-1
Hello there
255
65535
-1
Hello there
1234
1234
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto Int8Var = uc.DefineVariable("x As Int8 = -1");
   auto Int16Var = uc.DefineVariable("y As Int16 = -1");
   auto StrVar = uc.DefineVariable("MyStr = 'Hello there'");
   cout << uc.EvalStr("x") << endl;
   cout << uc.EvalStr("y") << endl;
   cout << uc.EvalStr("MyStr") << endl;

   auto xPtr = uc.DefineVariable("xPtr As Pointer"); // General pointer
   auto yPtr = uc.DefineVariable("yPtr As Int16u Ptr"); // pointer specific to unsigned Int16
   auto yPtrB = uc.DefineVariable("yPtrB As Int16 Ptr = AddressOf(y)"); // Using AddressOf
   auto StrPtr = uc.DefineVariable("StrPtr As String Ptr");
   xPtr.ValuePtr(Int8Var.ValueAddr()); // Sets the pointer address
   yPtr.ValuePtr(Int16Var.ValueAddr()); // Note: address of signed Int16 going to an unsigned Ptr
   StrPtr.ValuePtr(StrVar.ValueAddr());

   // Note: for the ints we are now returning unsigned values; so -1 turns into positive numbers
   cout << uc.EvalStr("ValueAt(Int8u, xPtr)") << endl; // Type required because it's defined as generar pointer
   cout << uc.EvalStr("ValueAt(yPtr)") << endl; // Type name not needed because it's defined as Int16u Ptr
   cout << uc.EvalStr("ValueAt(yPtrB)") << endl;
   cout << uc.EvalStr("ValueAt(StrPtr)") << endl;

   // Iterate through uc.ItemOf(ItemIs.DataType, n).Name()
   // to see data type names you can use with ValueAt

   auto OtherInt = uc.DefineVariable("OtherInt As Int16 = 1234");
   uc.DataTypeOf(BuiltInType::Integer_16).SetScalar(Int16Var.ValueAddr(), OtherInt.ValueAddr());

   cout << uc.EvalStr("OtherInt") << endl;
   cout << uc.EvalStr("ValueAt(yPtrB)") << endl;





}
				
			
-1
-1
Hello there
255
65535
-1
Hello there
1234
1234
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim Int8Var = uc.DefineVariable("x As Int8 = -1")
      Dim Int16Var = uc.DefineVariable("y As Int16 = -1")
      Dim StrVar = uc.DefineVariable("MyStr = 'Hello there'")
      Console.WriteLine(uc.EvalStr("x"))
      Console.WriteLine(uc.EvalStr("y"))
      Console.WriteLine(uc.EvalStr("MyStr"))
      
      Dim xPtr = uc.DefineVariable("xPtr As Pointer") '// General pointer
      Dim yPtr = uc.DefineVariable("yPtr As Int16u Ptr") '// pointer specific to unsigned Int16
      Dim yPtrB = uc.DefineVariable("yPtrB As Int16 Ptr = AddressOf(y)") '// Using AddressOf
      Dim StrPtr = uc.DefineVariable("StrPtr As String Ptr")
      xPtr.ValuePtr(Int8Var.ValueAddr()) '// Sets the pointer address
      yPtr.ValuePtr(Int16Var.ValueAddr()) '// Note: address of signed Int16 going to an unsigned Ptr
      StrPtr.ValuePtr(StrVar.ValueAddr())
      
      '// Note: for the ints we are now returning unsigned values; so -1 turns into positive numbers
      Console.WriteLine(uc.EvalStr("ValueAt(Int8u, xPtr)")) '// Type required because it's defined as generar pointer
      Console.WriteLine(uc.EvalStr("ValueAt(yPtr)")) '// Type name not needed because it's defined as Int16u Ptr
      Console.WriteLine(uc.EvalStr("ValueAt(yPtrB)"))
      Console.WriteLine(uc.EvalStr("ValueAt(StrPtr)"))
      
      '// Iterate through uc.ItemOf(ItemIs.DataType, n).Name()
      '// to see data type names you can use with ValueAt
      
      Dim OtherInt = uc.DefineVariable("OtherInt As Int16 = 1234")
      uc.DataTypeOf(BuiltInType.Integer_16).SetScalar(Int16Var.ValueAddr(), OtherInt.ValueAddr())
      
      Console.WriteLine(uc.EvalStr("OtherInt"))
      Console.WriteLine(uc.EvalStr("ValueAt(yPtrB)"))
      
      
      
      
      
   End Sub
End Module
				
			
-1
-1
Hello there
255
65535
-1
Hello there
1234
1234
Explore 600+ other examples