I'm trying to increment the name of the file based on the number associated with the filename. If I make the variable postFix an int type, it gives an error (understandably) since I can't concatenate an int to a string type.
In that case how do I increment string variable?
for (int i = 0; i <= 10; i++)
{
std::string postFix = "1"; // int postFix = 1 gives an error
std::cout << (std::string("Image" + postFix + std::string(".png")));
}
You can use std::to_string to create a std::string from your int value.
for (int i = 0; i <= 10; i++)
{
std::cout << "Image" + std::to_string(i+1) + ".png";
}
Although in this case you might as well just use the stream operator<<
for (int i = 0; i <= 10; i++)
{
std::cout << "Image" << i+1 << ".png";
}
You don't; you use an integer variable, and make a string representation of it to build the file name: std::to_string(n)
int value = atoi(postFix.c_str());
value++;
postFix = std::to_string(value);
int value = std::stoi(postFix);? en.cppreference.com/w/cpp/string/basic_string/stol
use std::to_string
for (int i = 0; i <= 10; i++)
{
int postFix = 1;
std::cout << (std::string("Image" + std::to_string(postFix) + std::string(".png")));
}
It seems you're getting it more complicated than necessary.
for (int i = 1; i <= 10; i++) {
std::cout << "Image" << i << ".png";
}
or
for (int i = 1; i <= 10; i++) {
std::string filename = "Image" + std::to_string(i) + ".png";
// do something with filename
}
to_string(int) appeared in C++11.
Write simply
std::cout << std::string("Image" ) + std::to_string( i + 1 ) + ".png";
Or even like
std::cout << "Image" + std::to_string( i + 1 ) + ".png";
Or you can define at first a string
std:;string = "Image" + std::to_string( i + 1 ) + ".png";
and then output it
std::cout << s;
Increment the int 'Number' as your wish, then convert it into string and finally append it with the file name (or exactly where you want).
Headers needed:
#include <iomanip>
#include <locale>
#include <sstream>
#include <string> // this should be already included in <sstream>
And to convert the 'Number' to 'String' do the following:
int Number = 123; // number to be converted to a string
string Result; // string which will contain the result
ostringstream convert; // stream used for the conversion
convert << Number; // insert the textual representation of 'Number' in the characters in the stream
Result = convert.str(); // set 'Result' to the contents of the stream
// 'Result' now is equal to "123"
This operation can be shorten into a single line:
int Number = 123;
string String = static_cast<ostringstream*>( &(ostringstream() << Number) )->str();
Reference taken from here.
