如果用户没有输入任何内容或输入错误，如何重新输入用户的输入？

Question

I'm working on a mastermind game as a university project. The user has to guess a number of colors with a certain order. The problem is if the user inputs something like "erd" instead of "red" his chance would be lost. I wanted to make the code somehow that it would say "invalid color!" when he inputs something invalid and let him re-enter his thing. I kinda did it but there is a small problem, look at the code below:

void guess(char guessBall[4][10]) {
  for (int i = 0; i < 4; i++) {
    cin >> guessBall[i];
    if (strcmp(guessBall[i], "red") == 0 || strcmp(guessBall[i], "blue") == 0 ||
        strcmp(guessBall[i], "green") == 0 ||
        strcmp(guessBall[i], "yellow") == 0 ||
        strcmp(guessBall[i], "white") == 0 ||
        strcmp(guessBall[i], "black") == 0) {
      continue;
    } else {
      cout << "invalid color!";
      i--;
    }
  }
}

The problem is that if the user inputs like this: red blue WRONG black instead of pressing enter each time, it would say "invalid color!" and let him re-enter, but the order of the colors would be wrong. example:

INPUT: "red WRONG green blue"
OUTPUT: Invalid Color!
INPUT: "Red"
OUTPUT: Your guess: red green blue red

the guess should be "red red green blue".

Would be thankful if u guys gave any suggestions. Full code as requested:EDIT: I seemingly am unable to paste the code on my post, some parts of it get messed up and i don't know what to do. The only thing I could think of was pasting the code on a CodePile page. here u go: https://www.codepile.net/pile/4rYRMJ93 i think codepile is a safe place ?

Answer 1

The cin will take the inputs in the order you type them. Your input example is "red WRONG green blue red". My suggestion is that you use the debugger and put a break point a continue and one in the else statement and you can see what is going on.

My suggestion would be to make one part that handle the input and one part validating the answer. Then you can call the input function until the validation is correct.

Answer 2

The cin will processes the input in the order it was typed in. Since "red WRONG green blue" is typed in before the second "red," this second red is placed at the end of the input stream. Your code is probably fine, just type colors one at a time when testing your program.