Concatenate integer with string to format string

Question

I have to concatenate integer with a string as follows, user will enter a number e.g. 1 and it will be be placed in string like this:

std::remove("C:/Users/pcname/Desktop/files/1.txt");

If user enters 2, it's like

std::remove("C:/Users/pcname/Desktop/files/2.txt");

It's pretty basic but I'm having issue with this I tried to use operator+ with this but that did not work.

Be more specific. Showcase the problematic code that "doesn't work". — tambre, Mar 08 '17 at 19:10
Please search StackOverflow before posting. I recommend the keywords "stackoverflow c++ concatenate string integer". — Thomas Matthews, Mar 08 '17 at 20:29

score 1 · Answer 1 · answered Mar 08 '17 at 19:10

1

You can use std::to_string to convert an integer to a std::string, then use concatenation

int file_num = 1;
std::remove("C:/Users/pcname/Desktop/files/" + std::to_string(file_num) + ".txt");

Otherwise trying to do something like

"C:/Users/pcname/Desktop/files/" + file_num

is actually doing pointer arithmetic and will not produce the string you think it will

answered Mar 08 '17 at 19:10

Cory Kramer

[Error] 'to_string' is not a member of 'std' – Sikander Mar 08 '17 at 19:12
And in case you cannot use >C++11, `boost::lexical_cast` – Ceros Mar 08 '17 at 19:12
kindly elaborate i am unable to get your second point boost::lexical_cast – Sikander Mar 08 '17 at 19:14
boost is an external library that you need to include in your project – Ceros Mar 08 '17 at 19:15
but you (if you can) should use modern c++ that is C++11 and above – Ceros Mar 08 '17 at 19:16
so if i dont want to use boost::lexical_cast how can i fix this any suggestions please. – Sikander Mar 08 '17 at 19:20
Then you have to fallback on old funtions: http://stackoverflow.com/questions/5590381/easiest-way-to-convert-int-to-string-in-c – Ceros Mar 08 '17 at 19:21
i used this std::remove("C:/Users/pcname/Desktop/files/" + std::to_string(1) + ".txt"); and this is what i get [Error] 'to_string' is not a member of 'std' – Sikander Mar 08 '17 at 19:29
1

That's because you are not using C++11 or above. http://en.cppreference.com/w/cpp/string/basic_string/to_string – Ceros Mar 08 '17 at 19:30

1 Answers1