我写东西后想在consol中有第一行..我怎么能得到？

Question

During programming, I just want to first row in console for example:

First step: (in console result)

a

a

a

a

a

// this program maybe like this
 for(int i=0;i<5;i++)
    cout<<"a"<<endl;

Second step: This part is what I ask, I want to get the form below (in console):

ab

ab

ab

ab

ab

Exactly what I want is after first step, I can't return to first row just I want to write 'b' but what I know is I can't be back to first row.

So how can I do?

Answer 1

you can't modify a console line afterwards. to give the impression that you do you may clear the console and then rewrite the whole output.

Answer 2

You can use control sequences if your terminal supports. For instance, you can try the following codes:

int main() {
    for (int i = 0; i < 5; i++) {
        cout << 'a' << endl;
    }

    cout << '\033' << "[5A"; // move the cursor 5 cells up
    cout << '\033' << "[1C"; // 1 cells forward
    for (int i = 0; i < 5; i++) {
        cout << 'b';
        cout << '\033' << "[1D"; // 1 cells down
        cout << '\033' << "[1B"; // 1 cells back
    }
    return 0;
}