[SOLVED] How to get first two chars from a string and use the two chars in another string

How to get first two chars from a string and use the two chars in another string

I would like to get the first two chars from my string. Lets say my string dbdir = "Dir" and my other string test = "20122". I want to get the first two chars from test and combine it with dbdir string. So the result would be a string Dir20 then I want to use the combined string in another string for a file.

Here is my code

std::string dbdir = "Dir";
std::string test = "20122";

//strip first two chars from test//
std::string result_of_test_strip = ;

std::string combined = ""+ dbdir + result +"";
CString fileToOpen = "\"\\\\CAR\\VOL1\\Docs\\PRE\\15\\" + result_of_test_strip.c_str() +  "\\" + filenum.c_str() + ".prt" + "\"";

Suggested answer @therainmaker

      std::string dbdir = "Dir";
      std::string test = "20122";
      std::string result = test.substr(0, 2); 
      std::string combined = dbdir + result;

      CString fileToOpen = "\"\\\\CAR\\VOL1\\Docs\\PRE\\15\\" + combined.c_str() + "\\" + filenum.c_str() + ".prt" + "\"";

I get this error in CString fileToOpen ---> error C2110: cannot add two pointers Error executing cl.exe.

Solution

You can use the substr function to extract any relevant portion of a string.

In your case, to extract the first two characters, you can write

string first_two = test.substr(0, 2) // take a substring of test starting at position 0 with 2 characters

Another method for the first two characters might be

string first_two;
first_two.push_back(test[0]);
first_two.push_back(test[1]);

Also, in your string_combined line, you don't need to add an empty string "" at the beginning and end. The following line will work as well:

string combined = dbdir + result;