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Thread: Return-statement with no value

  1. #1
    Join Date
    Jan 2012
    Posts
    83
    Qt products
    Qt4
    Platforms
    Windows

    Default Return-statement with no value

    Hello!

    I am facing a problem.
    I want to use the conten of a file bt I have to check first if the file is opened.
    I am receiving th efollowing error message: "return-statement with no value, in function returning 'QStringList"

    My question: How to stop the process if the file can not be opened, since "return-statement does not work here?
    break-statement can be used only in a loop.

    Here is my code.

    Qt Code:
    1. QStringList myWindow::open(QString &fileName)
    2. {
    3. QFile file(fileName);
    4.  
    5. if(!file.open(QIODevice::ReadOnly))
    6. {
    7. QMessageBox::critical(this, "Warning", "Open a file please");
    8. return;
    9. }
    10.  
    11. // I do something here
    12. }
    To copy to clipboard, switch view to plain text mode 

    Many thanks in advance.

  2. #2
    Join Date
    Jan 2006
    Location
    Graz, Austria
    Posts
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    Qt products
    Qt3 Qt4 Qt5
    Platforms
    Unix/X11 Windows

    Default Re: Return-statement with no value

    Your method has a return type of QStringList, so all exits from it must return a QStringList object.

    Qt Code:
    1. return QStringList();
    To copy to clipboard, switch view to plain text mode 

    Cheers,
    _

  3. #3
    Join Date
    Jan 2012
    Posts
    83
    Qt products
    Qt4
    Platforms
    Windows

    Default Re: Return-statement with no value

    Many thanks!!!

    I have gone the half of the way.

    I have avoided willingly to indicate the path to the file after returning an empty QStringList, and the program crashes. Is there any way to ovoid this problem?

    Many thanks in advance.


    Added after 22 minutes:


    Many thanks one more time. I can mark this subjet as resolved. The crashing problem was in the function calling the open() function.

    Many thanks!
    Last edited by Stanfillirenfro; 18th January 2014 at 19:29.

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