string Date comparison

[Apollo1376]

Hi,

I have a vector<string> Date, which contains all the dates. I will be given a starting date and the ending date. I want to compare the 'staring date' with the dates in the Date vector. I am getting an error while I try to do this.

suppose Date vector has the date of the form

Date
12/31/2007
12/30/2007
12/29/2007
.
.
.
12/01/2007

I am given the staring date as 12/10/2007 and ending date as 12/17/2007. I want the index at which these dates occur. I want to compare my starting and ending strings and get the index out of it. This is what I have done so far

float Get_Price(string startingDate, string endingDate)
{
    int Lowindex, Highindex;
    for( int i=0; i<Date.size(), i++)
    {
        if ( strcmp (startingDate, Date.at(i)) == 0 )
              Lowindex = i;
        if ( strcmp (endingDate, Date.at(i)) == 0 )
              Highindex = i;
 
    }
}

I am getting an error! where am I doing wrong?

Thanks
Raam

[Savage]

Hi,

I have a vector<string> Date, which contains all the dates. I will be given a starting date and the ending date. I want to compare the 'staring date' with the dates in the Date vector. I am getting an error while I try to do this.

suppose Date vector has the date of the form

Date
12/31/2007
12/30/2007
12/29/2007
.
.
.
12/01/2007

I am given the staring date as 12/10/2007 and ending date as 12/17/2007. I want the index at which these dates occur. I want to compare my starting and ending strings and get the index out of it. This is what I have done so far

float Get_Price(string startingDate, string endingDate)
{
int Lowindex, Highindex;
for( int i=0; i<Date.size(), i++)
{
if ( strcmp (startingDate, Date.at(i)) == 0 )
Lowindex = i;
if ( strcmp (endingDate, Date.at(i)) == 0 )
Highindex = i;

}
}

I am getting an error! where am I doing wrong?

Thanks
Raam

You said that it's vector of strings,right?And strcmp takes as a argument a c style string which is a char array.Use c_str() to get char array and then compare ,or you can use overloaded equality operator:

e.g

if(startingDate==Date.at(i))

Savage

[Ganon11]

std::string has overloaded the == operator? I didn't know that! Here I am using std::string::compare(std::string other) like a fool...

[Savage]

std::string has overloaded the == operator? I didn't know that! Here I am using std::string::compare(std::string other) like a fool...

Yep,here's the list of all overloaded string operators.

Savage

[Apollo1376]

Thank you. Initially, I tried to use If (startingDate == Date.at(i) ) but it doesn't give me the compilation error but its core dumping. Is there anyway to do this with out converting into a char string?

Thanks
Raam

[Savage]

Thank you. Initially, I tried to use If (startingDate == Date.at(i) ) but it doesn't give me the compilation error but its core dumping. Is there anyway to do this with out converting into a char string?

Thanks
Raam

Core dumping?

Are you sure that this statement produce it?

Perhaps error is somewhere else.

About your question you can use compare Gannon mentioned but == is based on it so the result will be the same.

Savage

[Apollo1376]

To check whether its within that for loop. I tried to print out my Date vector.

for( int i=0; i<=Date.size(); i++)
{
cout<< Date.at(i)<<endl;
}

This function is printing all the dates but its never coming out of the loop. Do you have any ideas why its happening?

Thanks
Raam

[Apollo1376]

Here is my full code:

#include <iostream>
#include <string>
#include <vector>
 
using namespace std;
using std::cerr;
using std::cout;
using std::endl;
 
#include<fstream>
 
using std::ifstream;
using std::vector;
 
#include<cstdlib> // this is exit function
vector<string> Date;
vector<float> Price;
 
// Read the values from CompFinSumAssi.txt
 
void writeData(string date, vector<string>& Date, vector<float>& Price, float);
 
int Load_Price_Data() {
  ifstream indata;
 
  vector<float> priceVector; //variable for input price value
  vector<string> dateVector; //variable for input date
  float price;
  string date;
 
  indata.open("SumAssiData.txt"); //opens the file
  if(!indata) {
    cerr << "Error: file could not be opened" << endl;
    exit(1);
  }
 
  // Read the SumAssiData file
  indata>> date>> price;
 
  while( !indata.eof() ) { // keep reading until end-of-file
    writeData(date, Date, Price, price);
    indata>>date >> price;
  }
 
  indata.close();
  cout<<"Size of Date is: "<<Date.size()<<endl;
  cout <<"End of file is reached" << endl;
  return 0;
}
 
 
void writeData(string date, vector<string>& Date, vector<float>& Price, float price) {
 
  // vector<string> Date;
  //vector<float> Price;
    Date.push_back(date);
    Price.push_back(price);
    //cout<<Date.size()<<endl;
 
    //  for(int i=0; i<Date.size(); i++) {
    //cout<<Date.at(i)<<endl;
    //}
  //cout<<" size of Date is: "<<Date.size()<<endl;
 
}
 
float Get_Price(string startingDate, string endingDate) {
 
  int Lowindex, Highindex;
  float sumPrice, Avgindex, AveragePrice;
 
  cout<< " I reached here: Get_Price"<<endl;
  cout<<" Date size is:"<<Date.size()<<endl;
  cout<< "startingDate is:" <<startingDate<<endl;
 
  for(int i=0; i<=Date.size(); i++)
    {
      cout<<Date.at(i)<<endl;
    }
  cout<<" I came out of cout for loop for Date" <<endl;
 // This is self is not printing 
 
 
  for(int i=0; i<=Date.size(); i++){
    cout<<"I am inside the for loop"<<endl;
 
    if(startingDate == Date.at(i) ) {
      cout<<" I am inside the if statement"<<endl;
      // if( strcmp( startingDate, Date.at(i) ) == 0 )
      Lowindex = i;
      cout<<" Low index is: "<< Lowindex<<endl; 
    }
 
    if(endingDate == Date.at(i) ) {
      cout<< " I am inside the endingDate if"<<endl;
      // if( strcmp( endingDate, Date.at(i) > == 0 )
      Highindex = i;
      cout<<" high Index is: "<<Highindex<<endl;
    } else
      cout<< " No date found: "<<endl;
  }
 
  sumPrice = 0;
  for(int j=Lowindex; j<=Highindex; j++) {
    sumPrice = sumPrice + Price.at(j);
  } 
 
  Avgindex = Highindex-Lowindex;
  AveragePrice = sumPrice/Avgindex;
 
  cout<< "Average price is: "<<AveragePrice<<endl;
  return AveragePrice;
}
 
int main() {
  Load_Price_Data();
  string startingDate, endingDate;
  startingDate = "8/16/2004";
  endingDate = "9/15/2004";
  Get_Price(startingDate, endingDate);
}

[Ganon11]

Don't use "i <= Date.size();" This will run past the last element in your vector. If your vector has three strings (say "12/01/89", "12/02/89", and "12/03/89"), then Date.size() returns 3, but these elements are stored in Date[0], Date[1], and Date[2], respectively. Using "i = 0; i <= Date.size()" will mean i becomes 0, 1, 2, and 3 - but Date[3] doesn't exist.

Use i < Date.size() instead.

[Apollo1376]

Thanks, It worked.

Raam