I am trying to compare a string from getline(file,line) with a std::string s="mmee" :
if (line==s){}
but this is never executed. why?? inside the file i have:
mmee
hello
hey
How to trim the spaces or enter from string line?
4 Answers
Your code is correct.
Please check your input file to verify there is no leading or trailing spaces.
answered Jan 16, 2012 at 11:50
Shamim Hafiz - MSFT
22.2k44 gold badges122 silver badges183 bronze badges
1 Comment
Angel Dream
i had some problems with some permissions
First of all why do you think that will get executed.
as mmee hello hey is part of the same line in the file, when you do a getline line will contain the whole line and not just mmee. Hence the if condition would fail.
Look at this link for trimming spaces.
Comments
You can remove the space by using
std::remove(astring.begin(), astring.end(), ' ');
and after that you can compare the string.
check out the link:: http://www.cplusplus.com/forum/beginner/863/
You can compare to String : http://www.cplusplus.com/reference/string/string/compare/
2 Comments
Angel Dream
(astring.begin(),astring.end(),' ') is there a space or no/
mayur rahatekar
yes Their is a sapce ' '...Just check this link cplusplus.com/forum/beginner/863
std::getline() by default reads to the first new-line character. You can specify the character to which you want the function to read, like this:
getline(file, line, ' '); // not the space between single quote chars
This would read only "mmee" part of your example file (mmee hello hey).
EDIT: It is how I read your example. People who edited the OP just assumed that the input file is mmee\nhello\nhey
1 Comment
Daniel Fischer
Reasonable assumption, the three words were all on separate lines, just not indented, so they were rendered on one line before the edit.
printf("'%s' == '%s'\n", line, s.c_str());so that you will see any leading or trailing spaces. Also compare string lengths to make sure all characters are printable.