Question

handwriten code for calculate button be able to delcare varables and name constants,use parse to capture input use formulas in assignment statments,and display formated output on a form

Answer 1

Note :- This code is written in C++ program.

1)It will take arguments through command line, two operands

2) It will parse the arguments stored in argv to get the operation ( + , - , * , / ) that is to be performed.

3) And then it will convert the String to Integer (stoi function)  to do the arithmetic operation.

4) Final Result will be displayed.

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#include <iostream>
#include <string>
using namespace std;

main (int argc, char **argv)
{
std::string token;
size_t pos = 0;
std::string inputStr;
std::string delimiterPlus = "+";
std::string delimiterSub = "-";
std::string delimiterMul = "*";
std::string delimiterDiv = "/";
int FinalResult = 0;
int opr1,opr2=0;
bool operatorFlag = false;
  
cout << "You have entered " << argc << " arguments:" << "\n";

for (int i = 0; i < argc; ++i)
{
cout << "argv= "<<argv[i] << "\n";
inputStr = argv[i];
}

//Addition of 2 numbers
while ((pos = inputStr.find (delimiterPlus)) != std::string::npos)
{
//int opr1,opr2;
token = inputStr.substr (0, pos);
//std::cout << "token Plus=" <<token << std::endl;
opr1=stoi(token);
operatorFlag = true;
inputStr.erase (0, pos + delimiterPlus.length ());
}
//cout << "LastInput Plus=" << inputStr << std::endl;
opr2=stoi(inputStr);
  
if(operatorFlag){
FinalResult = opr1 + opr2;
operatorFlag = false;
}
  
//Substraction of two numbers
while ((pos = inputStr.find (delimiterSub)) != std::string::npos)
{
token = inputStr.substr (0, pos);
//std::cout << "token Sub=" <<token << std::endl;
opr1=stoi(token);
operatorFlag = true;
inputStr.erase (0, pos + delimiterSub.length ());
}
  
// cout << "Opr1 Sub=" << opr1 << std::endl;
  
// cout << "LastInput Sub=" << inputStr << std::endl;
opr2=stoi(inputStr);
  
if(operatorFlag){
FinalResult = opr1 - opr2;
operatorFlag = false;
}
      
//Multiplication of two numbers
while ((pos = inputStr.find (delimiterMul)) != std::string::npos)
{
token = inputStr.substr (0, pos);
// std::cout << "token mul=" <<token << std::endl;
opr1=stoi(token);
operatorFlag = true;
inputStr.erase (0, pos + delimiterMul.length ());
}
  
//cout << "Opr1 mul=" << opr1 << std::endl;
  
//cout << "LastInput mul=" << inputStr << std::endl;
opr2=stoi(inputStr);
  
if(operatorFlag){
FinalResult = opr1 * opr2;
operatorFlag = false;
}
  
//Division of two numbers
while ((pos = inputStr.find (delimiterDiv)) != std::string::npos)
{
token = inputStr.substr (0, pos);
//std::cout << "token Div=" <<token << std::endl;
opr1=stoi(token);
operatorFlag = true;
inputStr.erase (0, pos + delimiterDiv.length ());
}

// cout << "Opr1 Div=" << opr1 << std::endl;
  
//cout << "LastInput Div=" << inputStr << std::endl;
opr2=stoi(inputStr);
  
if(operatorFlag){
FinalResult = opr1/opr2;
operatorFlag = false;
}

  
cout<<"Final Result= " << FinalResult <<std::endl;
  
return 0;
}