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Convert an string operation to integer [duplicate]

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Hi fellow programmers,
I am creating a calculator in C#
and I have a string variable math which contains 100 * 5 - 2
How can I display its output which is 498 in my console?
My code is this:
String math = "100 * 5 - 2";
Console.WriteLine(math);
Console.ReadLine(); // For Pause
So basically, what my code will give me is the string itself which 100 * 5 - 2
but I want it to give me 498 as a result.
Idea about this is pretty much appreciated.
Thanks

Regular Expression evaluation can be done using DataTable.Compute method (from MSDN) :
Computes the given expression on the current rows that pass the filter
criteria.
Try this:
using System.Data;//import this namespace
string math = "100 * 5 - 2";
string value = new DataTable().Compute(math, null).ToString();

Simply try this
String math = (100 * 5 - 2).ToString();
I don't know, Why you want more complex? It's very easy ..
And if you want surely that,You can do that by using EvaluateExpression
public int EvaluateExpression(string math )
{
return Convert.ToInt32(math);
}
........................
String math = "100 * 5 - 2";
int result = EvaluateExpression(math );
Console.WriteLine(result );
See this discussions
Evaluating string "3*(4+2)" yield int 18
Update:
If those values came from input textbox, then write this way
String math = txtCalculator.Text.Trim();
int result = EvaluateExpression(math );
Console.WriteLine(result );
And also you can find out some pretty answer from this discussion
Is it possible to compile and execute new code at runtime in .NET?
Update 2:
Finally I have tried this sample for you :
My full code for class library
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text.RegularExpressions;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Xml.XPath;
public partial class _Default : Page
{
protected void Page_Load(object sender, EventArgs e)
{
String math = "100 * 5 - 2";
Console.WriteLine(Evaluate(math));
}
public static double Evaluate(string expression)
{
var xsltExpression =
string.Format("number({0})",
new Regex(#"([\+\-\*])").Replace(expression, " ${1} ")
.Replace("/", " div ")
.Replace("%", " mod "));
// ReSharper disable PossibleNullReferenceException
return (double)new XPathDocument
(new StringReader("<r/>"))
.CreateNavigator()
.Evaluate(xsltExpression);
// ReSharper restore PossibleNullReferenceException
}
}

You can compile code from string at runtime and execute it:
using Microsoft.CSharp;
using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
namespace DynamicCalcTest
{
class Program
{
static void Main(string[] args)
{
var result = new DynamicCalculator<double>("2 + 2 * 2").Execute();
}
}
public class DynamicCalculator<T>
{
private MethodInfo _Method = null;
public DynamicCalculator(string code)
{
_Method = GetMethodInfo(code);
}
public T Execute()
{
return (T)_Method.Invoke(null, null);
}
private MethodInfo GetMethodInfo(string code)
{
var tpl = #"
public static class Calculator
{{
public static double Calc()
{{
return {0};
}}
}}";
var finalCode = string.Format(tpl, code);
var parameters = new CompilerParameters();
parameters.ReferencedAssemblies.Add("mscorlib.dll");
parameters.GenerateInMemory = true;
parameters.CompilerOptions = "/platform:anycpu";
var options = new Dictionary<string, string> { { "CompilerVersion", "v4.0" } };
var c = new CSharpCodeProvider(options);
var results = c.CompileAssemblyFromSource(parameters, finalCode);
var type = results.CompiledAssembly.GetExportedTypes()[0];
var mi = type.GetMethod("Calc");
return mi;
}
}
}

How to Access correctly to Positions Property in a LinePlot with Ilnumerics?

i would like to access to the coordinate information in a LinePlot, i wanto to use the Property LinePlot.Positions as show in the following code:
using System;
using System.Collections.Generic;
using System.Text;
using ILNumerics.Data;
using ILNumerics.Drawing.Plotting;
using ILNumerics.Drawing;
using ILNumerics;
using static ILNumerics.ILMath;
using System.Linq;
namespace TestConsoleUI2
{
class Program
{
static void Main(string[] args)
{
Array<double> xx = linspace(10, 15, 5);
Array<double> yy = linspace(8, 90, 5);
LinePlot myLinePlot = new LinePlot(xx, yy);
RetArray<float> p = myLinePlot.Positions;
}
}
}
Nevertheless i got an System.NullReferenceException i have debugged and the data exists at that moment,
can anyone help me?
Regards

After try and error i found the solution that is working for me.
using System;
using System.Collections.Generic;
using System.Text;
using ILNumerics.Data;
using ILNumerics.Drawing.Plotting;
using ILNumerics.Drawing;
using ILNumerics;
using static ILNumerics.ILMath;
using System.Linq;
namespace TestConsoleUI2
{
class Program
{
static void Main(string[] args)
{
Array<double> xx = linspace(10, 15, 5);
Array<double> yy = linspace(8, 90, 5);
LinePlot myLinePlot = new LinePlot(xx, yy);
PositionsBuffer p = myLinePlot.Line.Positions;
}
}
}

How can I remove the last two numbers from a number that's a double before making it a string?

I have this number in C#
Double a = 1.2345678
What I would like is for it to look like this after it's made into a string:
1.23456

First, convert it to string.
for example the string is defined as S.
then apply this method:
S.Remove(S.Length -2);

You can acheive that in many ways:
Code:
using System;
using System.Linq;
using System.Text;
namespace RemovingLastTwoNumber
{
class Program
{
static void Main(string[] args)
{
// Method 1.
double number = 1.2345678;
string numberInStringFormat = number.ToString();
string TargetNumber = numberInStringFormat.Substring(0, numberInStringFormat.Length - 2);
Console.WriteLine(number);
Console.WriteLine(TargetNumber);
// Method 2.
string _TargetNumber = Math.Round(number, 5).ToString();
Console.WriteLine(_TargetNumber);
// Method 3.
var characters = number.ToString().ToArray();
var __Characters = characters.Take(7);
StringBuilder __targetNumber = new StringBuilder();
foreach (var character in __Characters)
{
__targetNumber.Append(character);
}
Console.WriteLine(__targetNumber);
}
}
}

Link combo box and parallel array

I need help linking or mapping a combo box to a parallel array in C#. I have a class project where I need to create a payroll system that displays the Net Pay after taxes.
I want to link parallel arrays that have all the employee information needed for payroll to the option selected in the combo box. I feel like I almost have it, but I don't know how to link the option selected from the combo box and the parallel arrays I have set up.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace ZNSPayrollSystem
{
public partial class ZNSPayrollSystem : Form
{
public ZNSPayrollSystem()
{
InitializeComponent();
string[] arr = { "001 Peters", "002 Barnes", "003 Harris" };
cboEmp.DataSource = arr.ToArray();
}
private void btnCalc_Click(object sender, EventArgs e)
{
//parallel arrays
int[] empID = { 001, 002, 003 };
string[] empName = { "James Peters", "Sarah Barnes", "Candice Harris" };
double[] hrsWorked = { 40, 40, 40 };
double[] empWage = { 55.50, 65.50, 75.70 };
//declarations
double dblTaxRate = 8.2 / 100;
double dblNetPay;
double dblGrossPay;
double dblTaxWithheld;
dblGrossPay = hrsWorked[] * empWage[];
dblTaxWithheld = dblGrossPay * dblTaxRate;
dblNetPay = dblGrossPay - dblTaxWithheld;
txtGross.Text = dblGrossPay.ToString();
txtTax.Text = dblTaxWithheld.ToString();
txtNetPay.Text = dblNetPay.ToString();
}
}
}

Use the SelectedIndex property of the Combobox:
int i = cboEmp.SelectedIndex;
if (i != -1)
{
dblGrossPay = hrsWorked[i] * empWage[i];
}
i == -1 means nothing is selected. You may want to handle this separately to avoid getting any exceptions.

convert visio vba method into c#

Hello I would like to convert this vba method into C#. I am trying to get the IDs of a selection and print them out. In particular I am having trouble converting the GetIDs() method(a built in method within visio vba) into C#.
Public Sub getCapabilityRectIDs()
Dim vsoSelection1 As Visio.Selection
Dim selectionIDs() As Long
Set vsoSelection1 = Application.ActiveWindow.Page.CreateSelection(visSelTypeByLayer, visSelModeSkipSuper, "Capability")
Application.ActiveWindow.Selection = vsoSelection1
Call vsoSelection1.GetIDs(selectionIDs)
For i = 0 To UBound(selectionIDs)
Debug.Print selectionIDs(i)
Next i
End Sub
This is what I have so far in C#
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using Visio = Microsoft.Office.Interop.Visio;
class Program
{
static void Main(string[] args)
{
//create the object that will do the drawing
VisioDrawer Drawer = new VisioDrawer();
Drawer.selectShpLayer("Capability");
}
}
class VisioDrawer
{
public Visio.Application VisApp;
public static Visio.Page acPage;
public Visio.Selection LayerSelection;
public VisioDrawer()
{
//create the application
VisApp = new Visio.Application();
VisApp.Documents.Open(#"............. - abc.vsdm");
ActiveDoc = VisApp.ActiveDocument;
acPage = VisApp.ActivePage;
}
public void selectShpLayer (string layerName){
Int i = 0;
long[] lngRowIDs;
//this selects the shapes of the selected layer
LayerSelection = acPage.CreateSelection(Microsoft.Office.Interop.Visio.VisSelectionTypes.visSelTypeByLayer, Microsoft.Office.Interop.Visio.VisSelectMode.visSelModeOnlySuper,layerName);
LayerSelection.GetIDs(lngRowIDs);
for (i = 0; i < lngRowIDs.Length; i++)
{
Debug.Write(lngRowIDs[i]);
}
}
}
Thanks in advance!

I created a visio doc and drew 3 simple shapes. I then created a layer called "cool" and added those 3 shapes to it.
I don't understand enough about the shape selection, you had visSelModeOnlySuper which may work for you, but did not work for the case I created. The default is visSelModeSkipSuper (which worked for me)
Here's the API page that describes how to use the createSelection:
https://msdn.microsoft.com/en-us/library/office/ff765565.aspx
Here is my sample code:
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using Visio = Microsoft.Office.Interop.Visio;
class Program
{
static void Main(string[] args)
{
//create the object that will do the drawing
VisioDrawer Drawer = new VisioDrawer();
Drawer.selectShpLayer("cool");
}
}
class VisioDrawer
{
public Visio.Application VisApp;
public static Visio.Page acPage;
public Visio.Selection LayerSelection;
public VisioDrawer()
{
//create the application
VisApp = new Visio.Application();
VisApp.Documents.Open(#"c:\temp\trial.vsdm");
acPage = VisApp.ActivePage;
}
public void selectShpLayer(string layerName)
{
int i = 0;
int[] lngRowIDs;
Array lngRowIDArray;
//this selects the shapes of the selected layer
LayerSelection = acPage.CreateSelection(Microsoft.Office.Interop.Visio.VisSelectionTypes.visSelTypeByLayer, Microsoft.Office.Interop.Visio.VisSelectMode.visSelModeSkipSuper, layerName);
LayerSelection.GetIDs(out lngRowIDArray);
lngRowIDs = (int[])lngRowIDArray;
for (i = 0; i < lngRowIDs.Length; i++)
{
Debug.Write("Object ID: " + lngRowIDs[i].ToString() + "\n");
}
}
}
And it produces this output:
Object ID: 1
Object ID: 2
Object ID: 3
If you change the debug line to this:
Debug.Write("Object ID: " + lngRowIDs[i].ToString() + " -- " + acPage.Shapes.ItemFromID[i].Name + "\n");
The output gets even more useful:
Object ID: 1 -- ThePage
Object ID: 2 -- Circle
Object ID: 3 -- Rectangle