程序運行時連續打印Do-While循環

Question

我的程序中使用了以下代碼：

do {
    if (numOfItems == 3 || numOfItems == 5 || numOfItems == 7 || numOfItems == 9) {
        addItems(numOfItems);

    } else {
        System.out.println("That number is out of range.");
        System.out.println("Please choose an odd number in the range of [1, 10] exclusively:");
        numOfItems = scan.nextInt();
    }
} while (numOfItems != 3 || numOfItems != 5 || numOfItems != 7 || numOfItems != 9);

在運行時，它會不斷重復我只想發生一次的方法。 如何使循環不斷重復進行驗證，但只運行一次該方法？

Answer 1

更換

while (numOfItems != 3 || numOfItems != 5 || numOfItems != 7 || numOfItems != 9);

與

while (numOfItems != 3 && numOfItems != 5 && numOfItems != 7 && numOfItems != 9);

更新資料

從您的評論到答案，您似乎需要執行以下操作：

do {
    numOfItems = scan.nextInt();
    if (numOfItems == 3 || numOfItems == 5 || numOfItems == 7 || numOfItems == 9) {
        addItems(numOfItems);

    } else {
        System.out.println("That number is out of range.");
        System.out.println("Please choose an odd number in the range of [1, 10] exclusively:");

    }
} while (numOfItems != 3 && numOfItems != 5 && numOfItems != 7 && numOfItems != 9);

但是，您可以對此進行優化，如下所示：

while ((numOfItems = scan.nextInt() != 3) && numOfItems != 5 && numOfItems != 7 && numOfItems != 9) {

            System.out.println("That number is out of range.");
            System.out.println("Please choose an odd number in the range of [1, 10] exclusively:");
}

addItems(numOfItems);

Answer 2

您可能要糾正

while (numOfItems != 3 || numOfItems != 5 || numOfItems != 7 || numOfItems != 9);

從此，這將永遠是正確的 。

如果您始終想執行語句的do{...}塊，則可以擺脫this（ do..while ）條件。 （“ ...我只想發生一次”）