Getline not working in while loop

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August undefined, 2024

WebSep 22, 2024 · Your current program is looping endlessly because getline returns std::basic_istream, so while (getline ()) will never equate to 'false'. As @0x499602D2 has stated, your program is working as intended, but the extraction from getline can only end in two ways, as indicated by the reference here: WebMay 18, 2024 · 1 Answer Sorted by: 2 The last line of the file doesn't end with a newline. Fix that with printf "\n" >>file_ref_col_master.txt Share Improve this answer Follow answered May 18, 2024 at 17:01 roaima 101k 14 127 245 Add a comment Your Answer By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

c++ - Getline is not working - Stack Overflow

WebWith an odd number of lines, the last line goes through getline $0, then getline tmp fails but you aren't checking the return status so this merely leaves tmp unchanged, and you end up printing the next-to-last line again. Share Improve this answer answered May 28, 2024 at 1:24 Gilles 'SO- stop being evil' 791k 190 1632 2134 Add a comment WebApr 14, 2014 · I am using getline () in a loop. During the first loop everything runs okay except for the last getline (). During the second loop the first getline () seems to have been skipped. Here is the loop: south west oxford bylaw

Trouble understanding using getline() in a while loop and why ... - Reddit

WebTo do this, I used getline() in a while loop. With short circuiting, I have a flag. Here is my code: vector booktitles; string title; while (getline(cin, title) && title != "stop") { cin.ignore(50, '\n'); booktitles.push_back(title); cin.ignore(50, '\n'); } But this does not work as expected. Instead, I have to type "stop" multiple times. WebJun 18, 2024 · getline() not working second time in a while loop c++while-loop 15,950 Solution 1 cin >> yes; Right there, the user enters a letter, let's say 'y'. Then hits enter. This stores 2 characters in the input buffer, 'y' and '\n'. The 'y' gets stored in yes, but the '\n' remains. When you get to here again: getline (cin, option); team cottage

Reading multiple lines from a file using getline () - Stack Overflow

How to use getline in a loop c++ - Stack Overflow

WebApr 21, 2011 · Try cin.ignore () when you use cin before getline () function void inputstu () { cout << "Enter roll Number:"; cin >> roll_no; cin.ignore (); //ignore the withspace and enter key cout << "Enter name:"; getline (cin, stu_name); } Share Improve this answer Follow edited Dec 9, 2024 at 16:11 Zoe stands with Ukraine ♦ 26.6k 21 117 149 WebNov 16, 2024 · Use this loop condition instead: while ( (ctr < (Nrow*Ncol)) && std::getline (myFile1, line)) This will end the loop when EITHER Nrow*Ncol items have been stored in the array OR std::getline () fails to read the next line in the file. That being said, consider using a std::vector instead of new []. teamco truck bodiesWebJul 1, 2024 · The reason is that getline () reads till enter is encountered even if no characters are read. So even if there is nothing in the third line, getline () considers it as a single line. Further observe the problem in the second line. The code can be modified to … team cotter curling

"WebDec 23, 2013 · getline, as it name states, read a whole line, or at least till a delimiter that can be specified. So the answer is "no", getline does not match your need. But you can do something like: inFile >> first_name >> last_name >> age; name = first_name + " " + last_name; Share Improve this answer Follow answered Dec 23, 2013 at 8:19 Johan … " - Getline not working in while loop

Getline not working in while loop

c++ - Do/While loop not looping - Stack Overflow

WebAug 3, 2024 · Potential Issues with using std::getline () While std::getline () is a very useful function, there could be some problems that you may face when using it along with some … WebApr 26, 2024 · This is because the Enter/Return you use to submit the info is getting extracted by getline (), which stops at the first '\n' character it sees. One way to fix it is use cin.ignore (), after your custom input. Mind that if reading from file, you should end the line after class input to get the same result as here.

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WebMar 31, 2014 · 1 1 ch is indeterminate when first used in this code, and as such even evaluating it is undefined behavior. You may want to fix that second. First, get rid of gets (), a function so vile it has been removed from the standard library. – WhozCraig Mar 31, 2014 at 7:11 1 Where have you used cin.getline (). I can't see it anywhere – coder hacker WebSep 2, 2012 · There are two overloads for std::getline: istream& getline ( istream& is, string& str, char delim ); istream& getline ( istream& is, string& str ); Three of your calls pass a literal string constant as the third parameter, where a single char is required. Use ' rather than " for character constants.

WebMar 12, 2015 · Your problem is that stream's error flags get set when getline finds more characters than the maximum set. (see the description at std::basic_istream::getline count-1 characters have been extracted (in which case setstate (failbit) is executed). and If the function extracts no characters (e.g. if count < 1), setstate (failbit) is executed. Web2 days ago · It reads a line and discards it. 10 being the confused would-be programmer's way of writing '\n'. The author of GetLine probably intended that it skip until the end of the line, but if the stream is already at the end of a line it will skip the next line. If there is a read error, it enters an infinite loop.

WebNov 1, 2024 · My problem is that I am able to use getline (file, string) to read the lines in the second file in the first pass of the loop but am unable to see the values when i try and run the loop again. here is the code: WebMar 1, 2013 · When this offset reaches the end, it stops the first loop, ( eof () returns false). You need to reset this internal position back to the beginning of the file, before reading again. You do that by saying: myFile.clear (); // clear stream flags and error state myFile.seekg (0, ios::beg); // reset read position before the second loop.

WebDec 30, 2011 · getline (cin, option); Since there's already a newline character in the buffer, getline has what it's looking for, and doesn't need to prompt the user. There are a few …

WebJun 30, 2024 · getline extracts characters from input and appends them to str until it meet one of the end conditions, in your situaton the end condition is the endline character '\n', because the default delimeter is the endline character. You may define your own delimeter getline (intput, str, $your_delemeter) , and do a little experiment. Share team cottage countryWebgetline (cin, option); Since there's already a newline character in the buffer, getline has what it's looking for, and doesn't need to prompt the user. There are a few solutions to this. You could add a call to cin.ignore () after cin >> yes. Or you could make yes a string, and use getline instead of operator>> there. Benjamin Lindley 99184 team couch liftWebwhile (getline(cin, line) && line != "&&") { While successfully got a line AND line is not "&&". Looks good. NOte: The new lines are stripped by the getline function because they're the token delimiter and leaving them in the returned token or leaving them in the stream would just cause problems. message = message + " " + line; Append line to ... team cotton candy genderWebThe above code is a C++ program that creates a Student Management System. The program takes in student data such as names, student numbers, DOB, Email and GPA, and stores it in an array. The program can add and remove students from the array, and also modify existing student data. The program can also print out a list of students and their ... team couch on zillowWebSep 11, 2024 · CS121/main.cpp. # include // allows for reading and writing from a file. //was getting an extra line so had to add an if statement to nullify the extra line from the file. myfile. close (); //closes the txt file. south west paddle boardingWebNov 10, 2012 · This do-while loop will execute at least one time, because the condition gets checked at the end of the loop execution. So even if the user does not press Y when asked the first time, this loop would have been executed once. After that, it will go on as long as the condition is fulfilled. Learn more about the do-while loop here. south-west pacificWebJan 13, 2014 · Std::getline itself does move the file towards the end – Gasim Jan 13, 2014 at 1:25 1 @Gasim, click on the link that chris provided to see why while (!eof ()) is "wrong". More specifically, it's not a good way to check this kind of loop since one must attempt to read the EOF before eof () is true. It doesn't tell you if you are "at" the EOF. team couch