Question

我的程序中使用了以下代码：

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);

，在运行时，不断重复我只想发生一次的方法。如何使循环不断重复验证，但只运行一次方法？

Answer 1

替换

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

与

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

<强>更新

从您的评论到答案，您似乎需要执行以下操作：

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，您可以将其优化为以下内容：

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

您可能想要更正

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

因为，它始终是 true 。

如果您始终要执行do..while语句块，则可以删除此（do{...}）条件。（“......我只想发生一次”）

在程序运行时，Do-While循环连续打印

2 个答案: