W+ mode is not working why ?

Question

I am using File.open ("filename","w+") but its does not showing anything when i replaced w+ with r its working. can you tell me why?

Answer 1

Well, you open a file for writing if you want to create it and/or add data to it. And you open a file for reading, if you just want to read the data from it.

You can't do both at the same time to one file (most applications create a virtual copy when working on a file in a more user-friendly way).

Answer 2

w+ is for writing, not "showing" (reading). It expects you to write something to the file.

Answer 3

so what is reading and writing mode ?

Answer 4

file.open("filename",iOS::in|iOS::out)