Is this a bug with getline(), or am I doing something wrong. Right way to use getline()?

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生来不讨喜
生来不讨喜 2021-01-13 03:58

It might not be a bug, but I don\'t know what is going wrong. My first entry is repeated for str1 on 2nd iteration, and is same way from then. Only first iteration goes goo

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  •  误落风尘
    2021-01-13 04:19

    Add

    cin.ignore( std::numeric_limits::max(), '\n' );
    

    after your

    cin >> c;
    

    Consider the following input:

        dog
        cat
        y
        owl
        fish
        n
    

    If we examine the characters that are present in the input stream individually, we'll see:

        d o g \n c a t \n y \n o w l \n f i s h \n n \n
    

    The first call to getline consumes dog\n; the second consumes cat\n, leaving this:

        y \n o w l \n f i s h \n n \n
    

    The first call to cin >> c consumes only y but not the subsequent newline, leaving this:

        \n o w l \n f i s h \n n \n
    

    Now, the fun begins: What happens during the next call to getline? Why it reads up to the next newline, of course. So the next call to getline returns an empty line, and leaves owl... in the input stream.

    The solution, as I outlined above, is to consume the remainder of the (now useless) input line.

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