uCalc API Version: 2.1.3-preview.2 Released: 6/17/2026

Warning

uCalc API Preview Release Notice:The documentation describes the intended behavior of the API. The current preview build contains incomplete features, unoptimized performance, and is subject to breaking changes.

Value()

Method

Product: 

Fast Math Parser

Class: 

Item

Retrieves the value of a variable, converting it to a double-precision floating-point number if necessary.

Syntax

Value()

Parameters

[None]

Return

double

The variable's value as a double-precision number. If the variable holds an integer or boolean, it is converted to a double.

Remarks

The Value() method is the primary getter for retrieving the numeric value of a variable represented by an Item object. It is designed to be a general-purpose accessor for any value that can be reasonably represented as a Double.

Type Conversion

This method automatically handles type conversion from other simple numeric types. If the underlying variable is an Integer or Boolean, its value is promoted to a Double before being returned. This provides flexibility and avoids the need for manual type-checking in many common scenarios.

Choosing the Right Accessor

uCalc provides several methods to retrieve a variable's value. Use the following guide to choose the most appropriate one:

MethodReturn TypeUse Case
Value()doubleThe default choice for any numeric value when you need a Double. Handles conversions automatically.
ValueInt32()intWhen you specifically need a 32-bit integer and want to avoid floating-point representation.
ValueBool()boolFor variables that hold boolean states.
ValueStr()stringThe universal getter. It can retrieve the value of any data type, including complex types, and return it as a string.

⚖️ Comparative Analysis

In a typical programming language like C# or C++, you access a variable's value directly by its name (e.g., double result = myVar;). In uCalc, the process is slightly different because you often interact with variables through their metadata object, the Item.

  • DefineVariable() returns an Item object.
  • This Item is a handle to the underlying variable in the uCalc engine.
  • Value() is the method you call on that Item to "dereference" it and retrieve its numeric content into your host application's environment.

This object-oriented approach allows for powerful runtime introspection (e.g., checking the variable's name or type via the Item object) before accessing its value.

⚡️ Direct Memory Binding: The High-Performance Alternative

While this Value() getter is used to retrieve a result, its corresponding setter (Value(newValue)) is used to push data into the uCalc engine. In performance-critical loops, repeatedly calling the setter can be inefficient.

As a high-performance alternative, uCalc supports direct memory binding. When defining a variable, you can pass the memory address of a host application variable directly to DefineVariable().

  • In C++: You can pass the address of a variable (e.g., &myHostVar).
  • In C#: This is possible within an unsafe context, typically by pinning the variable and passing its address.
  • In VB.NET: This is generally not supported.

When a variable is bound this way, the uCalc engine reads from and writes to your native variable's memory directly. This creates a "live link," eliminating the need to call the Value() setter inside a loop and offering the best possible performance for tight integrations.

Examples

DefineVariable examples
				
					using uCalcSoftware;

var uc = new uCalc();
var MyVar = uc.DefineVariable("MyVar");
var MyInt = uc.DefineVariable("MyInt As Int");
var MyStr = uc.DefineVariable("MyStr As String");
uc.DefineVariable("OtherStr = 'string type inferred'");
uc.DefineVariable("MyInt16 = Int16(100/3)"); // type inferred
uc.DefineVariable("MyBool = True"); // type inferred
uc.DefineVariable("MyComplex = 3 + 4*#i"); // type inferred

MyVar.Value(123);
MyInt.ValueInt32(456);
MyStr.ValueStr("This is a test");

Console.WriteLine("MyVar = " + uc.EvalStr("MyVar"));
Console.WriteLine("MyInt = " + uc.EvalStr("MyInt"));
Console.WriteLine("MyStr = " + uc.EvalStr("MyStr"));
Console.WriteLine("OtherStr = " + uc.EvalStr("OtherStr"));
Console.WriteLine("MyInt16 = " + uc.EvalStr("MyInt16"));
Console.WriteLine("MyBool = " + uc.EvalStr("MyBool"));
Console.WriteLine("MyComplex = " + uc.EvalStr("MyComplex"));
Console.WriteLine("---");
Console.WriteLine(MyVar.Value());
Console.WriteLine(MyInt.ValueInt32());
Console.WriteLine(MyStr.ValueStr());
Console.WriteLine("---");
Console.WriteLine(uc.ItemOf("MyVar").DataType.Name);
Console.WriteLine(uc.ItemOf("MyInt").DataType.Name);
Console.WriteLine(uc.ItemOf("MyStr").DataType.Name);
Console.WriteLine(uc.ItemOf("OtherStr").DataType.Name);
Console.WriteLine(uc.ItemOf("MyInt16").DataType.Name);
Console.WriteLine(uc.ItemOf("MyBool").DataType.Name);
Console.WriteLine("---");

var Expression = "x^2 * 10";
var VarX = uc.DefineVariable("x");
var ParsedExpr = uc.Parse(Expression);

Console.Write("Expression = ");
Console.WriteLine(Expression);
for (int x = 1; x <= 10; x++) {
   VarX.Value(x); // In C++ you can skip this by passing &x to DefineVariable
   Console.WriteLine("x = " + VarX.ValueStr() + "  Result = " + ParsedExpr.EvaluateStr());
}

ParsedExpr.Release();
VarX.Release();
				
			
MyVar = 123
MyInt = 456
MyStr = This is a test
OtherStr = string type inferred
MyInt16 = 33
MyBool = true
MyComplex = 3+4i
---
123
456
This is a test
---
double
int
string
string
int16
bool
---
Expression = x^2 * 10
x = 1  Result = 10
x = 2  Result = 40
x = 3  Result = 90
x = 4  Result = 160
x = 5  Result = 250
x = 6  Result = 360
x = 7  Result = 490
x = 8  Result = 640
x = 9  Result = 810
x = 10  Result = 1000
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto MyVar = uc.DefineVariable("MyVar");
   auto MyInt = uc.DefineVariable("MyInt As Int");
   auto MyStr = uc.DefineVariable("MyStr As String");
   uc.DefineVariable("OtherStr = 'string type inferred'");
   uc.DefineVariable("MyInt16 = Int16(100/3)"); // type inferred
   uc.DefineVariable("MyBool = True"); // type inferred
   uc.DefineVariable("MyComplex = 3 + 4*#i"); // type inferred

   MyVar.Value(123);
   MyInt.ValueInt32(456);
   MyStr.ValueStr("This is a test");

   cout << "MyVar = " + uc.EvalStr("MyVar") << endl;
   cout << "MyInt = " + uc.EvalStr("MyInt") << endl;
   cout << "MyStr = " + uc.EvalStr("MyStr") << endl;
   cout << "OtherStr = " + uc.EvalStr("OtherStr") << endl;
   cout << "MyInt16 = " + uc.EvalStr("MyInt16") << endl;
   cout << "MyBool = " + uc.EvalStr("MyBool") << endl;
   cout << "MyComplex = " + uc.EvalStr("MyComplex") << endl;
   cout << "---" << endl;
   cout << MyVar.Value() << endl;
   cout << MyInt.ValueInt32() << endl;
   cout << MyStr.ValueStr() << endl;
   cout << "---" << endl;
   cout << uc.ItemOf("MyVar").DataType().Name() << endl;
   cout << uc.ItemOf("MyInt").DataType().Name() << endl;
   cout << uc.ItemOf("MyStr").DataType().Name() << endl;
   cout << uc.ItemOf("OtherStr").DataType().Name() << endl;
   cout << uc.ItemOf("MyInt16").DataType().Name() << endl;
   cout << uc.ItemOf("MyBool").DataType().Name() << endl;
   cout << "---" << endl;

   auto Expression = "x^2 * 10";
   auto VarX = uc.DefineVariable("x");
   auto ParsedExpr = uc.Parse(Expression);

   cout << "Expression = ";
   cout << Expression << endl;
   for (int x = 1; x <= 10; x++) {
      VarX.Value(x); // In C++ you can skip this by passing &x to DefineVariable
      cout << "x = " + VarX.ValueStr() + "  Result = " + ParsedExpr.EvaluateStr() << endl;
   }

   ParsedExpr.Release();
   VarX.Release();
}
				
			
MyVar = 123
MyInt = 456
MyStr = This is a test
OtherStr = string type inferred
MyInt16 = 33
MyBool = true
MyComplex = 3+4i
---
123
456
This is a test
---
double
int
string
string
int16
bool
---
Expression = x^2 * 10
x = 1  Result = 10
x = 2  Result = 40
x = 3  Result = 90
x = 4  Result = 160
x = 5  Result = 250
x = 6  Result = 360
x = 7  Result = 490
x = 8  Result = 640
x = 9  Result = 810
x = 10  Result = 1000
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim MyVar = uc.DefineVariable("MyVar")
      Dim MyInt = uc.DefineVariable("MyInt As Int")
      Dim MyStr = uc.DefineVariable("MyStr As String")
      uc.DefineVariable("OtherStr = 'string type inferred'")
      uc.DefineVariable("MyInt16 = Int16(100/3)") '// type inferred
      uc.DefineVariable("MyBool = True") '// type inferred
      uc.DefineVariable("MyComplex = 3 + 4*#i") '// type inferred
      
      MyVar.Value(123)
      MyInt.ValueInt32(456)
      MyStr.ValueStr("This is a test")
      
      Console.WriteLine("MyVar = " + uc.EvalStr("MyVar"))
      Console.WriteLine("MyInt = " + uc.EvalStr("MyInt"))
      Console.WriteLine("MyStr = " + uc.EvalStr("MyStr"))
      Console.WriteLine("OtherStr = " + uc.EvalStr("OtherStr"))
      Console.WriteLine("MyInt16 = " + uc.EvalStr("MyInt16"))
      Console.WriteLine("MyBool = " + uc.EvalStr("MyBool"))
      Console.WriteLine("MyComplex = " + uc.EvalStr("MyComplex"))
      Console.WriteLine("---")
      Console.WriteLine(MyVar.Value())
      Console.WriteLine(MyInt.ValueInt32())
      Console.WriteLine(MyStr.ValueStr())
      Console.WriteLine("---")
      Console.WriteLine(uc.ItemOf("MyVar").DataType.Name)
      Console.WriteLine(uc.ItemOf("MyInt").DataType.Name)
      Console.WriteLine(uc.ItemOf("MyStr").DataType.Name)
      Console.WriteLine(uc.ItemOf("OtherStr").DataType.Name)
      Console.WriteLine(uc.ItemOf("MyInt16").DataType.Name)
      Console.WriteLine(uc.ItemOf("MyBool").DataType.Name)
      Console.WriteLine("---")
      
      Dim Expression = "x^2 * 10"
      Dim VarX = uc.DefineVariable("x")
      Dim ParsedExpr = uc.Parse(Expression)
      
      Console.Write("Expression = ")
      Console.WriteLine(Expression)
      For x  As Integer = 1 To 10
         VarX.Value(x) '// In C++ you can skip this by passing &x to DefineVariable
         Console.WriteLine("x = " + VarX.ValueStr() + "  Result = " + ParsedExpr.EvaluateStr())
      Next
      
      ParsedExpr.Release()
      VarX.Release()
   End Sub
End Module
				
			
MyVar = 123
MyInt = 456
MyStr = This is a test
OtherStr = string type inferred
MyInt16 = 33
MyBool = true
MyComplex = 3+4i
---
123
456
This is a test
---
double
int
string
string
int16
bool
---
Expression = x^2 * 10
x = 1  Result = 10
x = 2  Result = 40
x = 3  Result = 90
x = 4  Result = 160
x = 5  Result = 250
x = 6  Result = 360
x = 7  Result = 490
x = 8  Result = 640
x = 9  Result = 810
x = 10  Result = 1000
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