Qt Programming Language



  • @annabelle
    There you are, you've found the command window it sends its output to, and made it wait to exit till you press Enter, so you have time to read the output!

    However, I don't think your output can correspond exactly to what you have shown as your current program code in the screenshot? Two reasons:

    • Your output shows only Hello world!. But your code has 4 lines of output statements, we are not seeing the last 3 of them.

    • At line 18 you have the close-curly-brace to mark the end of your main() function definition. But I do not see the open-curly-brace to start the block? You should have an open-curly-brace after line 10 (int main()) and before line 11? That should mean the code you show does not compile.

    Your Build log window shows it running the Hello World.exe executable but it does not show it compiling the source. Do you actually have an old Hello World.exe executable sitting there from a previous, successful build against different source, which is what it is running?

    EDIT Aha! I can see in your IDE the title of the tab you are showing reads:

    *Hello Word!.cpp
    

    Note that * (asterisk) at the start of the filename. Editors do that to indicate that you have altered the text of the file in the editor pane but you have not saved it back to the file. That means the code as you show it has not been passed to the compiler, and it is indeed running the executable (no re-compilation) that was last successfully compiled. If you make/made the open-curly-brace change I said then this code would compile, and produce 4 lines of output.

    BTW: I'm not sure, but when I looked for you at what people were saying about this output window from CodeBlocks I think someone was claiming that in one of its "settings" (available somewhere inside the IDE) there is some kind of "Pause [for key press] at end of program before closing command output window". If you can find that you could avoid having to put the std::getline() at the end of your program.


  • Qt Champions 2018

    @annabelle yeah, it seems to work somehow.

    The output screen shows Hello World!.

    The only strang thing is: according to your code there should have been more lines of output (all the lines you added after hello world).

    Are you sure the latest code is compiled and you are not running an older version of your program?



  • @aha_1980 said in Qt Programming Language:

    @annabelle yeah, it seems to work somehow.

    The output screen shows Hello World!.

    The only strange thing is: according to your code there should have been more lines of output (all the lines you added after hello world).

    Are you sure the latest code is compiled and you are not running an older version of your program?

    This time I am running the newest version of the code, and here's what I get.
    0_1564319940533_fccd4ff9-c4b5-43ca-8a5d-d77139ca77f1-image.png
    0_1564320044318_fccf42fa-8cc7-444e-afe0-84f37c7bd057-image.png


  • Moderators

    @annabelle said in Qt Programming Language:

    This time I am running the newest version of the code

    Unfortunately, your latest code contains an error so it cannot be compiled. This means you are still running the old version. As a result, your output screen only contains "Hello world!" and nothing else.

    Does your screenreader report the error details to you? You should have heard, "error: expected initializer before 'std'". Did you hear that?

    Anyway, the error message is telling you that something is missing before 'std' on line 11. In your case, you are missing the open curly braces { after main(). Punctuation is very important in C++ code, so you must pay careful attention to them.



  • @jksh said in Qt Programming Language:

    @annabelle said in Qt Programming Language:

    This time I am running the newest version of the code

    Unfortunately, your latest code contains an error so it cannot be compiled. This means you are still running the old version. As a result, your output screen only contains "Hello world!" and nothing else.

    Does your screenreader report the error details to you? You should have heard, "error: expected initializer before 'std'". Did you hear that?

    Anyway, the error message is telling you that something is missing before 'std' on line 11. In your case, you are missing the open curly braces { after main(). Punctuation is very important in C++ code, so you must pay careful attention to them.

    My screenreader didn't tell me that particular error. Should I create a separate line with just an { on it?


  • Qt Champions 2018

    @annabelle yes, please add { on a new line directly after the line with main.



  • @aha_1980 said in Qt Programming Language:

    @annabelle yes, please add { on a new line directly after the line with main.

    Here's a screenshot of a new version.
    0_1564349705120_92e06ec3-7ee3-44f7-8297-8c26d2c7491c-image.png
    Here's where I'm confused. There's an error message in a few places that says, "cout in namespace std does not name a type.". What does this mean? Also, it seems that when I just put an { on a blank line, Codeblocks automatically puts a line below with a couple spaces, followed by a line with a single }. What's up with that, I wonder?


  • Moderators

    @annabelle said in Qt Programming Language:

    when I just put an { on a blank line, Codeblocks automatically puts a line below with a couple spaces, followed by a line with a single }. What's up with that, I wonder?

    Code::Blocks was trying to be helpful. Often, when people type {, they also want a corresponding }. The "couple of spaces" marks the location where people normally type in their code. (The code goes between { and }).

    However, you already had the closing } on your last line, so Code::Blocks ended up introducing another error. You must always check the characters that are automatically typed by your IDE. If it is not appropriate, you must remove it.

    Here's where I'm confused. There's an error message in a few places that says, "cout in namespace std does not name a type.". What does this mean?

    This error was caused when a } was inserted into your code. std::cout is not a type, so it can only be used inside a function body, between { and }. You will learn more about types and functions as you work through the learncpp.com tutorial.



  • @jksh said in Qt Programming Language:

    @annabelle said in Qt Programming Language:

    when I just put an { on a blank line, Codeblocks automatically puts a line below with a couple spaces, followed by a line with a single }. What's up with that, I wonder?

    Code::Blocks was trying to be helpful. Often, when people type {, they also want a corresponding }. The "couple of spaces" marks the location where people normally type in their code. (The code goes between { and }).

    However, you already had the closing } on your last line, so Code::Blocks ended up introducing another error. You must always check the characters that are automatically typed by your IDE. If it is not appropriate, you must remove it.

    Here's where I'm confused. There's an error message in a few places that says, "cout in namespace std does not name a type.". What does this mean?

    This error was caused when a } was inserted into your code. std::cout is not a type, so it can only be used inside a function body, between { and }. You will learn more about types and functions as you work through the learncpp.com tutorial.

    Now I'm getting an error that says, "Expected Unqualified ID before Return"
    And another that says, "Expected Declaration before }". What am I doing wrong? It seems I'm following the tutorial closely, but I'm stuck.


  • Moderators

    @annabelle said in Qt Programming Language:

    What am I doing wrong? It seems I'm following the tutorial closely, but I'm stuck.

    Accuracy is very important in programming. You must follow the tutorial down to the nearest character.

    Now I'm getting an error that says, "Expected Unqualified ID before Return"
    And another that says, "Expected Declaration before }".

    Interpreting and fixing errors is also a very important part of programming. Always focus on the first error message, because fixing that will likely remove many subsequent errors.

    Anyway, "Expected Unqualified ID before Return" is probably caused by more issues in punctuation -- for example, a { that doesn't have a matching }. I can't see your latest code so I can't find the exact error.

    It might be easier to erase the contents of main.cpp and type them out again carefully. See if you can restore your working "Hello World" code first. After it builds and runs without errors, start making modifications.



  • @annabelle
    As I said before, when you show us these screenshots we need to see the code file being compiled open in the main pane, so that we can see what you have written. You need to do that every time you want to ask a question about your code!


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