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.

DefineVariable

Method

Product: 

Fast Math Parser

Class: 

uCalc

Defines a new variable or array within the uCalc engine, with an optional initial value and data type.

Syntax

DefineVariable(string, ADDR, DataType)

Parameters

definition
string
Text containing the variable definition, including its name, optional type, and initial value.
variableAddress
ADDR
(Default = 0)
Optional memory address of a variable in the host program. If provided, the uCalc variable becomes a direct proxy to the host variable.
targetType
DataType
(Default = Empty)
Optional data type for the variable. If omitted, the type is inferred from the initial value or defaults to the engine's `DefaultDataType`.

Return

Item

An Item object representing the newly defined variable.

Remarks

DefineVariable is the primary method for creating variables and arrays within a uCalc instance. It uses a flexible string-based syntax that allows for defining a variable's name, data type, and initial value in a single statement. This is the counterpart to DefineConstant, with the key difference that variables can be modified at runtime.

⚙️ Syntax Breakdown

The definition string follows a simple pattern:

"VariableName [As DataType] [= InitialValueExpression]"

  • VariableName: The name of the variable. Must follow the alphanumeric token rules, which can be inspected via uc.ItemOf("_Token_Alphanumeric").Regex().
  • As DataType (Optional): Explicitly assigns a data type (e.g., Int, String, Bool).
  • = InitialValueExpression (Optional): Assigns an initial value. The expression is evaluated, and its result becomes the variable's starting value.

If no initial value is provided, the variable is initialized to the default for its type (e.g., 0 for numbers, "" for strings).

💡 Type System

uCalc employs a flexible type system for variables:

  • Explicit Typing: Use the As keyword to specify a type (e.g., "MyInt As Int").
  • Type Inference: If As is omitted but an initial value is given, uCalc infers the type (e.g., "MyStr = 'hello'" becomes a String).
  • Default Typing: If neither a type nor an initial value is specified, the variable receives the engine's default data type, which can be managed with DefaultDataType.
  • Pointer Types: Append Ptr to a data type name to create a pointer variable (e.g., Int Ptr).

By default, variable names are not case-sensitive.

📊 Defining Arrays

You can define arrays in two ways:

  1. Fixed-Size Declaration: Specify the size within square brackets.uc.DefineVariable("MyArray[10] As Int"); // An array of 10 integers

  2. Initializer List: Leave the brackets empty and provide a comma-separated list of initial values in curly braces. The size is inferred from the list.uc.DefineVariable("MyStrings[] = {'apple', 'banana', 'cherry'}");

🔗 Memory Binding

A powerful feature of DefineVariable is its ability to bind a uCalc variable directly to a variable in your host application (C#, C++, etc.) via the variableAddress parameter. This creates a two-way link:

  • Changes to the host variable are immediately reflected in uCalc.
  • Changes made to the variable within a uCalc expression (e.g., Eval("myVar = 10")) directly modify the memory of the host variable.

This technique avoids the need for manually updating variables before each evaluation and is highly efficient. In C++, you can pass an address directly (e.g., &myHostVar). In C#, this typically requires pinning the object in memory using GCHandle within an unsafe context.

🆚 Comparative Analysis

vs. Statically-Typed Languages (C#, C++)

  • Declaration: In C# or C++, variables are declared with compile-time type safety (int x = 10;). uCalc's string-based approach ("x = 10") is dynamic, evaluated at runtime.
  • Flexibility: uCalc's method is ideal for scripting, configuration files, or user-defined formulas where variable names and types are not known at compile time.
  • Safety: The trade-off is a lack of compile-time checking. A typo in a variable name ("MyVarr = 10") will result in a runtime error, not a compiler error.

vs. Dynamic Languages (Python, JavaScript)

  • Syntax: The concept is similar to dynamic languages where variables are created on first assignment. However, uCalc provides optional strong typing (As Int), which is more akin to TypeScript than plain JavaScript.

The unique advantage of DefineVariable lies in its memory binding capability, which provides a level of integration with native code that is uncommon in most high-level expression evaluators.

To see all defined variables, you can use ListOfItems with the property ItemIs.Variable.

Examples

A minimal example defining a variable and using it in an expression.

ID: 305

See: DefineVariable 
				
					using uCalcSoftware;

var uc = new uCalc();
uc.DefineVariable("x = 10");
Console.WriteLine(uc.Eval("x * 5"));
				
			
50
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uc.DefineVariable("x = 10");
   cout << uc.Eval("x * 5") << endl;
}
				
			
50
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      uc.DefineVariable("x = 10")
      Console.WriteLine(uc.Eval("x * 5"))
   End Sub
End Module
				
			
50
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Defines variables with explicit types, inferred types, and default types.

ID: 306

See: DefineVariable 
				
					using uCalcSoftware;

var uc = new uCalc();
// Explicit type definition
uc.DefineVariable("explicitInt As Int = 123");

// Type inferred from the initial string value
uc.DefineVariable("inferredStr = 'hello'");

// Type defaults to Double as no type or value is given
var defaultVar = uc.DefineVariable("defaultVar");

Console.WriteLine($"explicitInt type: {uc.ItemOf("explicitInt").DataType.Name}");
Console.WriteLine($"inferredStr type: {uc.ItemOf("inferredStr").DataType.Name}");
Console.WriteLine($"defaultVar type: {defaultVar.DataType.Name}");
				
			
explicitInt type: int
inferredStr type: string
defaultVar type: double
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   // Explicit type definition
   uc.DefineVariable("explicitInt As Int = 123");

   // Type inferred from the initial string value
   uc.DefineVariable("inferredStr = 'hello'");

   // Type defaults to Double as no type or value is given
   auto defaultVar = uc.DefineVariable("defaultVar");

   cout << "explicitInt type: " << uc.ItemOf("explicitInt").DataType().Name() << endl;
   cout << "inferredStr type: " << uc.ItemOf("inferredStr").DataType().Name() << endl;
   cout << "defaultVar type: " << defaultVar.DataType().Name() << endl;
}
				
			
explicitInt type: int
inferredStr type: string
defaultVar type: double
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      '// Explicit type definition
      uc.DefineVariable("explicitInt As Int = 123")
      
      '// Type inferred from the initial string value
      uc.DefineVariable("inferredStr = 'hello'")
      
      '// Type defaults to Double as no type or value is given
      Dim defaultVar = uc.DefineVariable("defaultVar")
      
      Console.WriteLine($"explicitInt type: {uc.ItemOf("explicitInt").DataType.Name}")
      Console.WriteLine($"inferredStr type: {uc.ItemOf("inferredStr").DataType.Name}")
      Console.WriteLine($"defaultVar type: {defaultVar.DataType.Name}")
   End Sub
End Module
				
			
explicitInt type: int
inferredStr type: string
defaultVar type: double
Explore 600+ other examples
DefineVariable examples

ID: 17

See: DataType = [DataType], DefineVariable, EvaluateStr, ItemOf(string, int64, int), Name = [string], Value(), Value(double), ValueInt32(), ValueInt32(int32), ValueStr(bool), ValueStr(string) 
				
					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
Explore 600+ other examples
				
					#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
Explore 600+ other examples
				
					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
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
Arrays with DefineVariable

ID: 67

See: DefineVariable 
				
					using uCalcSoftware;

var uc = new uCalc();
var MyArray = uc.DefineVariable("MyArray[3]");
uc.DefineVariable("MyArrayStr[] = {'aa', 'bb', 'cc'}");

uc.Eval("MyArray[0] = 111; MyArray[1] = 222; MyArray[2] = 333");

Console.WriteLine(uc.EvalStr("MyArray[0]"));
Console.WriteLine(uc.EvalStr("MyArray[1]"));
Console.WriteLine(uc.EvalStr("MyArray[2]"));
Console.WriteLine(uc.EvalStr("MyArrayStr[0]"));
Console.WriteLine(uc.EvalStr("MyArrayStr[1]"));
Console.WriteLine(uc.EvalStr("MyArrayStr[2]"));
Console.WriteLine(MyArray.Count);
Console.WriteLine(uc.ItemOf("MyArrayStr").Count);
				
			
111
222
333
aa
bb
cc
3
3
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto MyArray = uc.DefineVariable("MyArray[3]");
   uc.DefineVariable("MyArrayStr[] = {'aa', 'bb', 'cc'}");

   uc.Eval("MyArray[0] = 111; MyArray[1] = 222; MyArray[2] = 333");

   cout << uc.EvalStr("MyArray[0]") << endl;
   cout << uc.EvalStr("MyArray[1]") << endl;
   cout << uc.EvalStr("MyArray[2]") << endl;
   cout << uc.EvalStr("MyArrayStr[0]") << endl;
   cout << uc.EvalStr("MyArrayStr[1]") << endl;
   cout << uc.EvalStr("MyArrayStr[2]") << endl;
   cout << MyArray.Count() << endl;
   cout << uc.ItemOf("MyArrayStr").Count() << endl;
}
				
			
111
222
333
aa
bb
cc
3
3
Explore 600+ other examples
				
					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim MyArray = uc.DefineVariable("MyArray[3]")
      uc.DefineVariable("MyArrayStr[] = {'aa', 'bb', 'cc'}")
      
      uc.Eval("MyArray[0] = 111; MyArray[1] = 222; MyArray[2] = 333")
      
      Console.WriteLine(uc.EvalStr("MyArray[0]"))
      Console.WriteLine(uc.EvalStr("MyArray[1]"))
      Console.WriteLine(uc.EvalStr("MyArray[2]"))
      Console.WriteLine(uc.EvalStr("MyArrayStr[0]"))
      Console.WriteLine(uc.EvalStr("MyArrayStr[1]"))
      Console.WriteLine(uc.EvalStr("MyArrayStr[2]"))
      Console.WriteLine(MyArray.Count)
      Console.WriteLine(uc.ItemOf("MyArrayStr").Count)
   End Sub
End Module
				
			
111
222
333
aa
bb
cc
3
3
Explore 600+ other examples
Using the parse-evaluate pattern for high-performance calculations in a loop with a changing variable w/ stopwatch.

ID: 1460

See: DefineVariable, Evaluate, Optimizing Performance in Loops, Parse, Value(double) 
				
					using uCalcSoftware;

var uc = new uCalc();
var variableX = uc.DefineVariable("x");
var userExpression = "x * 2 + 5";
var Total = 0.0;
var UpperBound = 1000000; // One million

// Parse the expression just once before the loop begins.
var parsedExpr = uc.Parse(userExpression);

var stopwatch = System.Diagnostics.Stopwatch.StartNew();
for (double x = 1; x <= UpperBound; x++) {
   variableX.Value(x);
   Total = Total + parsedExpr.Evaluate();
}
stopwatch.Stop();
//Uncomment the following line to reveal the actual speed:
//Console.WriteLine($"Elapsed Milliseconds: {stopwatch.ElapsedMilliseconds} ms");

Console.Write("Sum(1, "); Console.Write(UpperBound); Console.Write(", "); Console.Write(userExpression); Console.Write(") = "); Console.Write(Total);
				
			
Sum(1, 1000000, x * 2 + 5) = 1000006000000
Explore 600+ other examples
				
					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   auto variableX = uc.DefineVariable("x");
   auto userExpression = "x * 2 + 5";
   auto Total = 0.0;
   auto UpperBound = 1000000; // One million

   // Parse the expression just once before the loop begins.
   auto parsedExpr = uc.Parse(userExpression);


   for (double x = 1; x <= UpperBound; x++) {
      variableX.Value(x);
      Total = Total + parsedExpr.Evaluate();
   }

   cout << "Sum(1, " << UpperBound << ", " << userExpression << ") = " << (long long)Total;
}
				
			
Sum(1, 1000000, x * 2 + 5) = 1000006000000
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					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      Dim variableX = uc.DefineVariable("x")
      Dim userExpression = "x * 2 + 5"
      Dim Total = 0.0
      Dim UpperBound = 1000000 '// One million
      
      '// Parse the expression just once before the loop begins.
      Dim parsedExpr = uc.Parse(userExpression)
      
      Dim stopwatch = System.Diagnostics.Stopwatch.StartNew()
      For x  As Double = 1 To UpperBound
         variableX.Value(x)
         Total = Total + parsedExpr.Evaluate()
      Next
      stopwatch.Stop()
      '//Uncomment the following line to reveal the actual speed:
      '//Console.WriteLine($"Elapsed Milliseconds: {stopwatch.ElapsedMilliseconds} ms");
      
      Console.Write("Sum(1, ")
      Console.Write(UpperBound)
      Console.Write(", ")
      Console.Write(userExpression)
      Console.Write(") = ")
      Console.Write(Total)
   End Sub
End Module
				
			
Sum(1, 1000000, x * 2 + 5) = 1000006000000
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A quick start example showing defining a variable, a function, and evaluating an expression.

ID: 1296

See: DefineFunction, DefineVariable, Eval, Introduction 
				
					using uCalcSoftware;

var uc = new uCalc();
uc.DefineVariable("x = 10");
uc.DefineFunction("DoubleThis(n) = n * 2");

Console.WriteLine(uc.Eval("DoubleThis(x) + 5"));
				
			
25
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					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uc.DefineVariable("x = 10");
   uc.DefineFunction("DoubleThis(n) = n * 2");

   cout << uc.Eval("DoubleThis(x) + 5") << endl;
}
				
			
25
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					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      uc.DefineVariable("x = 10")
      uc.DefineFunction("DoubleThis(n) = n * 2")
      
      Console.WriteLine(uc.Eval("DoubleThis(x) + 5"))
   End Sub
End Module
				
			
25
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A minimal example defining a function inline to calculate the area of a rectangle.

ID: 296

See: DefineFunction, DefineVariable, Eval 
				
					using uCalcSoftware;

var uc = new uCalc();
uc.DefineVariable("x = 5");
uc.DefineFunction("Area(length, width) = length * width");
Console.WriteLine(uc.Eval("Area(4, x) + 7"));
				
			
27
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					#include <iostream>
#include "uCalc.h"

using namespace std;
using namespace uCalcSoftware;

int main() {
   uCalc uc;
   uc.DefineVariable("x = 5");
   uc.DefineFunction("Area(length, width) = length * width");
   cout << uc.Eval("Area(4, x) + 7") << endl;
}
				
			
27
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					Imports System
Imports uCalcSoftware
Public Module Program
   Public Sub Main()
      Dim uc As New uCalc()
      uc.DefineVariable("x = 5")
      uc.DefineFunction("Area(length, width) = length * width")
      Console.WriteLine(uc.Eval("Area(4, x) + 7"))
   End Sub
End Module
				
			
27
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