如果值相同，则停止while循环

Question

基本上，我有一个while循环，它检索被按下的按钮（这是一个棋子）的坐标，并通过这个循环查看是否可以移动

然而，同一国际象棋棋子的坐标不断地被输入，因此，如果棋子没有可用的移动，相同的消息会反复显示，直到按下不同的按钮，如果棋子没有移动，同样的事情会再次发生。 我该如何在每次点击一个页面时只打印一次相同的消息

我尝试使用do while循环，其中while循环中的条件是，如果坐标值与输入的坐标值不同，则只检查按钮是否有可用的移动。但这没什么区别吗

        while(!correctMove){
            do{
                fromXCo = s.getFromXInt();
                fromYCo = s.getFromYInt();
                toXCo = s.getToXInt();
                toYCo = s.getToYInt();

                    p = board.getPiece(fromXCo, fromYCo);

                    //checks if occupied co-ordinate, if not goes back out the loop and asks again.
                    if (!board.occupied(fromXCo, fromYCo)){
                        System.out.println("Please choose occupied co-ordinates \n");
                        correctMove = false;
                    }

                    //checks if the colour is the same as the player's. If not, asks for co-ordinates again.
                    if (p.getColour() != getPieces().getColour()){
                        System.out.println("Please move your own pieces \n");
                        correctMove = false;
                    }

                    //tells player their selected piece
                    System.out.println("Your selected piece is " + p.getChar());

                    //looks through available moves for piece
                    moves = p.availableMoves();

                    //if no moves available, asks for new co-ordinates.
                    if (moves == null){
                        System.out.println("No moves available for this piece \n");
                        correctMove = false;
                    }
                    else {

                        Move found = null;

                        for( Move m : moves){
                            //checks if move can be done
                            if (m.ToX() == toXCo && m.ToY() == toYCo){
                                //if move is allowed- exit loop
                                found = m; 

                                correctMove = true;

                            }
                        }

                        if (found == null) {
                            //if move can't be, ask for new co-ordinates
                            System.out.println("This move is not legal \n");
                            correctMove = false;

                        }   
                    }
                }while(fromXCo != s.getFromXInt() && fromYCo != s.getFromYInt() && toXCo != s.getToXInt() && toYCo != s.getToYInt());
            }

Answer 1

如果我正确理解了while的目的，那么如果没有选择带有合法移动的合法物品，用户可以重复选择。你不需要有两个while循环（内部的while看起来就像一个if）。我将这样做（伪代码）：

correctMove = false;
While(!correctMove) {
    square = inputNewSquare();
    if(isEmpty(square))
        "click on a piece"
    else if(pieceHasRightColor(square))
        "you can only move your own piece"
    else if(!pieceHasMove(square))
        "this piece has no legal move"
    else {
        //move(s) found, do stuff
        correctMove = true;
    }
}