In this blog, I’m create a Calculator using Visual studio c++

Description

This is simple calculator that contains four basic mathimatical functions for common calculation.

C++ code for the design

Calculator.h

#pragmaonce
#include<string.h>
#include<exception>
namespace CalculatorSam {
 
            usingnamespace System;
            usingnamespace System::ComponentModel;
            usingnamespace System::Collections;
            usingnamespace System::Windows::Forms;
            usingnamespace System::Data;
            usingnamespace System::Drawing;
 
            /// <summary>
            /// Summary for Calculator
            /// </summary>
            publicrefclassCalculator : public System::Windows::Forms::Form
            {public:
                        private: System::String^ value;
            private: System::Windows::Forms::Button^  btnClear;
            private: System::String^ OperatorSelected;
            public:
                        Calculator(void)
                        {
                                    InitializeComponent();
                                    //
                                    //TODO: Add the constructor code here
                                    //
                        }
 
            protected:
                        /// <summary>
                        /// Clean up any resources being used.
                        /// </summary>
                        ~Calculator()
                        {
                                    if (components)
                                    {
                                                delete components;
                                    }
                        }
            private: System::Windows::Forms::TextBox^  txtResult;
            protected:             private: System::Windows::Forms::Button^  btn1;
            private: System::Windows::Forms::Button^  btn2;
            private: System::Windows::Forms::Button^  btn3;
            private: System::Windows::Forms::Button^  btn4;
            private: System::Windows::Forms::Button^  btn5;
            private: System::Windows::Forms::Button^  btn6;
            private: System::Windows::Forms::Button^  btn7;
            private: System::Windows::Forms::Button^  btn8;
            private: System::Windows::Forms::Button^  btn9;
            private: System::Windows::Forms::Button^  btn0;
            private: System::Windows::Forms::Button^  btnEqual;
            private: System::Windows::Forms::Button^  btnDecimal;
            private: System::Windows::Forms::Button^  btnAdd;
            private: System::Windows::Forms::Button^  btnSub;
            private: System::Windows::Forms::Button^  btnMul;
            private: System::Windows::Forms::Button^  btnDiv;
 
            private:
                        /// <summary>
                        /// Required designer variable.
                        /// </summary>
                        System::ComponentModel::Container ^components;
 
#pragmaregion Windows Form Designer generated code
                        /// <summary>
                        /// Required method for Designer support - do not modify
                        /// the contents of this method with the code editor.
                        /// </summary>
                        void InitializeComponent(void)
                        {
                                    this->txtResult = (gcnew System::Windows::Forms::TextBox());
                                    this->btn1 = (gcnew System::Windows::Forms::Button());
                                    this->btn2 = (gcnew System::Windows::Forms::Button());
                                    this->btn3 = (gcnew System::Windows::Forms::Button());
                                    this->btn4 = (gcnew System::Windows::Forms::Button());
                                    this->btn5 = (gcnew System::Windows::Forms::Button());
                                    this->btn6 = (gcnew System::Windows::Forms::Button());
                                    this->btn7 = (gcnew System::Windows::Forms::Button());
                                    this->btn8 = (gcnew System::Windows::Forms::Button());
                                    this->btn9 = (gcnew System::Windows::Forms::Button());
                                    this->btn0 = (gcnew System::Windows::Forms::Button());
                                    this->btnEqual = (gcnew System::Windows::Forms::Button());
                                    this->btnDecimal = (gcnew System::Windows::Forms::Button());
                                    this->btnAdd = (gcnew System::Windows::Forms::Button());
                                    this->btnSub = (gcnew System::Windows::Forms::Button());
                                    this->btnMul = (gcnew System::Windows::Forms::Button());
                                    this->btnDiv = (gcnew System::Windows::Forms::Button());
                                    this->btnClear = (gcnew System::Windows::Forms::Button());
                                    this->SuspendLayout();
                                    // 
                                    // txtResult
                                    // this is textbox to show input numbers
                                    this->txtResult->Location = System::Drawing::Point(12, 24);
                                    this->txtResult->Name = L"txtResult";
                                    this->txtResult->Size = System::Drawing::Size(231, 20);
                                    this->txtResult->TabIndex = 0;
                                    // 
                                    // btn1
                                    // this is button  for 1
                                    this->btn1->Location = System::Drawing::Point(13, 71);
                                    this->btn1->Name = L"btn1";
                                    this->btn1->Size = System::Drawing::Size(45, 38);
                                    this->btn1->TabIndex = 1;
                                    this->btn1->Text = L"1";
                                    this->btn1->UseVisualStyleBackColor = true;
                                    this->btn1->Click += gcnew System::EventHandler(this, &Calculator::button_Click);
                                    // 
                                    // btn2
                                    // this is button  for 2
                                    this->btn2->Location = System::Drawing::Point(74, 71);
                                    this->btn2->Name = L"btn2";
                                    this->btn2->Size = System::Drawing::Size(45, 38);
                                    this->btn2->TabIndex = 2;
                                    this->btn2->Text = L"2";
                                    this->btn2->UseVisualStyleBackColor = true;
                                    this->btn2->Click += gcnew System::EventHandler(this, &Calculator:: button_Click);
                                    // 
                                    // btn3
                                    // this is button  for 3
                                    this->btn3->Location = System::Drawing::Point(135, 71);
                                    this->btn3->Name = L"btn3";
                                    this->btn3->Size = System::Drawing::Size(45, 38);
                                    this->btn3->TabIndex = 3;
                                    this->btn3->Text = L"3";
                                    this->btn3->UseVisualStyleBackColor = true;
                                    this->btn3->Click += gcnew System::EventHandler(this, &Calculator:: button_Click);
                                    // 
                                    // btn4
                                    // this is button  for 4
                                    this->btn4->Location = System::Drawing::Point(196, 71);
                                    this->btn4->Name = L"btn4";
                                    this->btn4->Size = System::Drawing::Size(45, 38);
                                    this->btn4->TabIndex = 4;
                                    this->btn4->Text = L"4";
                                    this->btn4->UseVisualStyleBackColor = true;
                                    this->btn4->Click += gcnew System::EventHandler(this, &Calculator:: button _Click);
                                    // 
                                    // btn5
                                    // this is button  for 5 
                                    this->btn5->Location = System::Drawing::Point(13, 123);
                                    this->btn5->Name = L"btn5";
                                    this->btn5->Size = System::Drawing::Size(45, 38);
                                    this->btn5->TabIndex = 5;
                                    this->btn5->Text = L"5";
                                    this->btn5->UseVisualStyleBackColor = true;
                                    this->btn5->Click += gcnew System::EventHandler(this, &Calculator:: button_Click);
                                    // 
                                    // btn6
                                    //this is button  for 6
                                    this->btn6->Location = System::Drawing::Point(74, 123);
                                    this->btn6->Name = L"btn6";
                                    this->btn6->Size = System::Drawing::Size(45, 38);
                                    this->btn6->TabIndex = 6;
                                    this->btn6->Text = L"6";
                                    this->btn6->UseVisualStyleBackColor = true;
                                    this->btn6->Click += gcnew System::EventHandler(this, &Calculator:: button_Click);
                                    // 
                                    // btn7
                                    // this is button  for 7 
                                    this->btn7->Location = System::Drawing::Point(135, 123);
                                    this->btn7->Name = L"btn7";
                                    this->btn7->Size = System::Drawing::Size(45, 38);
                                    this->btn7->TabIndex = 7;
                                    this->btn7->Text = L"7";
                                    this->btn7->UseVisualStyleBackColor = true;
                                    this->btn7->Click += gcnew System::EventHandler(this, &Calculator:: button_Click);
                                    // 
                                    // btn8
                                    // this is button  for 8
                                    this->btn8->Location = System::Drawing::Point(196, 123);
                                    this->btn8->Name = L"btn8";
                                    this->btn8->Size = System::Drawing::Size(45, 38);
                                    this->btn8->TabIndex = 8;
                                    this->btn8->Text = L"8";
                                    this->btn8->UseVisualStyleBackColor = true;
                                    this->btn8->Click += gcnew System::EventHandler(this, &Calculator:: button_Click);
                                    // 
                                    // btn9
                                    // this is button  for 9 
                                    this->btn9->Location = System::Drawing::Point(13, 175);
                                    this->btn9->Name = L"btn9";
                                    this->btn9->Size = System::Drawing::Size(45, 38);
                                    this->btn9->TabIndex = 9;
                                    this->btn9->Text = L"9";
                                    this->btn9->UseVisualStyleBackColor = true;
                                    this->btn9->Click += gcnew System::EventHandler(this, &Calculator:: button_Click);
                                    // 
                                    // btn0
                                    // this is button  for 0
                                    this->btn0->Location = System::Drawing::Point(74, 175);
                                    this->btn0->Name = L"btn0";
                                    this->btn0->Size = System::Drawing::Size(45, 38);
                                    this->btn0->TabIndex = 10;
                                    this->btn0->Text = L"0";
                                    this->btn0->UseVisualStyleBackColor = true;
                                    this->btn0->Click += gcnew System::EventHandler(this, &Calculator:: button_Click);
                                    // 
                                    // btnEqual
                                    // this is button  for =
                                    this->btnEqual->Location = System::Drawing::Point(196, 175);
                                    this->btnEqual->Name = L"btnEqual";
                                    this->btnEqual->Size = System::Drawing::Size(45, 38);
                                    this->btnEqual->TabIndex = 11;
                                    this->btnEqual->Text = L"=";
                                    this->btnEqual->UseVisualStyleBackColor = true;
                                    this->btnEqual->Click += gcnew System::EventHandler(this, &Calculator::btnOperation);
                                    // 
                                    // btnDecimal
                                    // this is button  for .
                                    this->btnDecimal->Location = System::Drawing::Point(135, 175);
                                    this->btnDecimal->Name = L"btnDecimal";
                                    this->btnDecimal->Size = System::Drawing::Size(45, 38);
                                    this->btnDecimal->TabIndex = 12;
                                    this->btnDecimal->Text = L".";
                                    this->btnDecimal->UseVisualStyleBackColor = true;
                                    this->btnDecimal->Click += gcnew System::EventHandler(this, &Calculator::btnDecimal_Click);
                                    // 
                                    // btnAdd
                                    // this is button  for +
                                    this->btnAdd->Location = System::Drawing::Point(13, 227);
                                    this->btnAdd->Name = L"btnAdd";
                                    this->btnAdd->Size = System::Drawing::Size(45, 38);
                                    this->btnAdd->TabIndex = 13;
                                    this->btnAdd->Text = L"+";
                                    this->btnAdd->UseVisualStyleBackColor = true;
                                    this->btnAdd->Click += gcnew System::EventHandler(this, &Calculator::btnOperation);
                                    // 
                                    // btnSub
                                    // this is button  for -
                                    this->btnSub->Location = System::Drawing::Point(74, 227);
                                    this->btnSub->Name = L"btnSub";
                                    this->btnSub->Size = System::Drawing::Size(45, 38);
                                    this->btnSub->TabIndex = 14;
                                    this->btnSub->Text = L"-";
                                    this->btnSub->UseVisualStyleBackColor = true;
                                    this->btnSub->Click += gcnew System::EventHandler(this, &Calculator::btnOperation);
                                    // 
                                    // btnMul
                                    // this is button  for *
                                    this->btnMul->Location = System::Drawing::Point(135, 227);
                                    this->btnMul->Name = L"btnMul";
                                    this->btnMul->Size = System::Drawing::Size(45, 38);
                                    this->btnMul->TabIndex = 15;
                                    this->btnMul->Text = L"*";
                                    this->btnMul->UseVisualStyleBackColor = true;
                                    this->btnMul->Click += gcnew System::EventHandler(this, &Calculator::btnOperation);
                                    // 
                                    // btnDiv
                                    // this is button  for / 
                                    this->btnDiv->Location = System::Drawing::Point(196, 227);
                                    this->btnDiv->Name = L"btnDiv";
                                    this->btnDiv->Size = System::Drawing::Size(45, 38);
                                    this->btnDiv->TabIndex = 16;
                                    this->btnDiv->Text = L"/";
                                    this->btnDiv->UseVisualStyleBackColor = true;
                                    this->btnDiv->Click += gcnew System::EventHandler(this, &Calculator::btnOperation);
                                    // 
                                    // btnClear
                                    // this is button  for clear
                                    this->btnClear->Location = System::Drawing::Point(12, 279);
                                    this->btnClear->Name = L"btnClear";
                                    this->btnClear->Size = System::Drawing::Size(45, 38);
                                    this->btnClear->TabIndex = 17;
                                    this->btnClear->Text = L"Clear";
                                    this->btnClear->UseVisualStyleBackColor = true;
                                    this->btnClear->Click += gcnew System::EventHandler(this, &Calculator::btnClear_Click);
                                    // 
                                    // Calculator
                                    // 
                                    this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
                                    this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
                                    this->ClientSize = System::Drawing::Size(258, 322);
                                    this->Controls->Add(this->btnClear);
                                    this->Controls->Add(this->btnDiv);
                                    this->Controls->Add(this->btnMul);
                                    this->Controls->Add(this->btnSub);
                                    this->Controls->Add(this->btnAdd);
                                    this->Controls->Add(this->btnDecimal);
                                    this->Controls->Add(this->btnEqual);
                                    this->Controls->Add(this->btn0);
                                    this->Controls->Add(this->btn9);
                                    this->Controls->Add(this->btn8);
                                    this->Controls->Add(this->btn7);
                                    this->Controls->Add(this->btn6);
                                    this->Controls->Add(this->btn5);
                                    this->Controls->Add(this->btn4);
                                    this->Controls->Add(this->btn3);
                                    this->Controls->Add(this->btn2);
                                    this->Controls->Add(this->btn1);
                                    this->Controls->Add(this->txtResult);
                                    this->Name = L"Calculator";
                                    this->Text = L"Calculator";
                                    this->Click += gcnew System::EventHandler(this, &Calculator::btnOperation);
                                    this->ResumeLayout(false);
                                    this->PerformLayout();
 
                        }
#pragmaendregion
                        private: bool IsNum;
//calling display function and passing the text of button clicked as string
            private: System::Void button_Click (System::Object^  sender, System::EventArgs^  e) {
                                                  if(OperatorSelected!=String::Empty && !IsNum)
                                                               txtResult->Text="";
                                                   Button^ button = (Button^)sender ;
                                                   txtResult->Text+=button->Text;
                                                   IsNum=true;
                                     }
//checking whether ‘.’ Is present in text box or not if present then no
             //action will be taken as there can be only one decimal point in a number
            //and if not then decimal will be added.
private: System::Void btnDecimal_Click(System::Object^  sender, System::EventArgs^  e) {
                                      System::String^ textBoxValue = txtResult->Text;
                                                 if(textBoxValue->IndexOf(".")<0)
                                                 {
                                                             if(textBoxValue->Length<=0)
                                                                         txtResult->Text+="0.";
                                                             else
                                                                         txtResult->Text+=".";
                                                 }
                         }
//this function perform all mathematical operation
private: System::Void btnOperation(System::Object^  sender, System::EventArgs^  e) {
                                      Button^ button = (Button^)sender ;
                                                try
                                                 {
                                                             if(!String::IsNullOrEmpty(OperatorSelected) && !String::IsNullOrEmpty(value))
                                                 {
//this condition perform addition operation
                                                             if(OperatorSelected=="+")
                                                             {
                                                                         txtResult->Text=Convert::ToString(Convert::ToDouble(value) + Convert::ToDouble(txtResult->Text));
 
                                                             }
//this condition perform  subtraction operation
 
                                                             elseif(OperatorSelected=="-")
                                                             {
                                                                         txtResult->Text=Convert::ToString(Convert::ToDouble(value) - Convert::ToDouble(txtResult->Text));
                                                             }
//this condition perform division operation
                                                             elseif(OperatorSelected=="/")
                                                             {
                                                                         txtResult->Text=Convert::ToString(Convert::ToDouble(value) / Convert::ToDouble(txtResult->Text));
                                                             }
//this condition perform division operation
 
                                                             elseif(OperatorSelected=="*")
                                                             {
                                                                         txtResult->Text=Convert::ToString(Convert::ToDouble(value) * Convert::ToDouble(txtResult->Text));
                                                             }
                                                             elseif(button->Text=="=")
                                                             {txtResult->Text=value;
                                                             }
                                                             value=txtResult->Text;
                                                    }
                                                    value=txtResult->Text;
                                                            OperatorSelected=button->Text;
                                                   IsNum=false;
                                                 }
                                                 catch(std::exception & ex)
                 {
                                                             txtResult->Text="";
                                                  }
                        
                         }
private: System::Void btnClear_Click(System::Object^  sender, System::EventArgs^  e) {
                                      txtResult->Text="";
                                                 value=String::Empty;
                         }
};
}

 Calculator.cpp

#include"Calculator.h"
usingnamespace CalculatorSam;
//Entry Point for Window form
void WinMain()
{
            Application::EnableVisualStyles();
            Application::SetCompatibleTextRenderingDefault(false);
            CalculatorSam::Calculator Form;
            Application::Run(%Form);
            Application::Exit();
            Environment::Exit(0);
}