out of bounds

I am trying to pass a string to a function and return the string to the main function.
I keep getting the following error:

terminate called after throwing an instance of 'std::out_of_range'
what(): basic_string::substr

I don't know what this means. Can anyone help me?
If I put the same code inside main, the program runs fine. I try to put the code into it's own function and then I get the above error message.

You need to post some of the code you have, specifically the parts that are causing the error. It's difficult to tell when we can't see what's going on.

Code:

---

using namespace std;

string parseColor(string);

int main ()
{
 string s;
 string info;
 string info2;

 cout << "Welcome to the Color Description Parser!" << endl;
 cout << endl;
 cout << "Enter your color description (on the next line): " << endl;
 getline(cin,s);

 info2= parseColor(s);

  cout << "In standard format, your color is:  " << info << endl;
  cout << "Goodbye!" << endl;

return 0;
}

string parseColor(string)
{
....
...
//I have a bunch of logic stuff in here that works fine if I put it in main


  //starting after the word "blue", find the first thing that isn't a space
  index_B2=s1.find_first_not_of(space,index7+4);
  index_B3=s1.find_first_of(junk,index_B2); //look for either a space or a comma
  colorBlue=s1.substr(index_B2,index_B3-index_B2);
  }
 
 info=color_name + " " + colorRed + " " + colorGreen + " " + colorBlue;

 }
return info;
}

---

please help.

OOPs

the line should have read:

Code:

---

info=parseColor(s);

---

Check the variable you are returning in parseColor. If it is local to the function then you can have troubles, as it is no longer valid outside of the function.

I changed the variable to be a global variable but i am still getting the same error message.

Check index_B2 against string::npos. Do the same with index_B3. If either of those are equal to string::npos then that's the problem. That indicates the call to find_xxx failed to find a match.

BTW, I'd switch back to a local variable instead of a global, I don't see anything wrong with your use of local vs global variables here.

Quote:

---

Originally Posted by Daved

I don't see anything wrong with your use of local vs global variables here.

---

I wasn't trying to imply not using a local variable, but wanted to see about using it correctly.

Code:

---

string parseColor(string)
{
 int index1, index2, index3;
 unsigned int index4;
 int index5, index6,index7;
 int index_Gr1,index_Gr2;
 int index_R1,index_R2,index_R3,index_R4;
 int index_G1,index_G2,index_G3,index_G4;
 int index_B1,index_B2,index_B3,index_B4;
 int index_A,index_B;
 int comma1,comma2;
 string space (" ");
 string junk=(" "",");
 string color_name;
 int s_length;
 string color_num1;
 string colorRed,colorGreen,colorBlue;
 string s,info;
 
 index1=s.find("color");
 index2=s.find_first_not_of(space,index1+5);
 index3=s.find_first_of(space,index2+1);
 color_name=s.substr(index2,index3-index2);
 s_length=s.length();

 index4=s.find("gray",index3+1);
//if color_name is gray do this:
 if(index4!=string::npos){
 index_Gr1=s.find_first_not_of(space,index4+4);
 index_Gr2=s.find(space,index_Gr1);
 color_num1=s.substr(index_Gr1,index_Gr2-index_Gr1);
 
 info=color_name+" "+color_num1+" "+color_num1+" "+color_num1;
}
 
//color_name is not gray
 else{
 index_A=s.find_first_not_of(space,index3+1);
 index_B=s.find_first_not_of(space,index_A+2);
 comma1=s.find(",",index_B+1);
 comma2=s.find(",",comma1+1);

---

I keep getting the same error message:
terminate called after throwing an instance of 'std::out_of_range'
what(): basic_string::substr

I don't understand why if I put the exact code in main it works fine.
Please help.

Code:

---

string parseColor(string s)
{

---

Surely you want to use the parameter that gets passed in? And not the uninitialized s that you create there at the bottom?

YES!!
that's it.
I am eternally grateful.
Thank you.