Question

我是java的新手，我正在尝试向用户询问输入，但我不希望用户能够输入两次相同的数字。这就是我的尝试

            g1 = iBox.getInteger("Enter your 1st number");
            g2 = iBox.getInteger("Enter your 2nd number");
                if(g1 == g2){
                    g2 =iBox.getInteger("Number used, please re-enter");
                }
            g3 = iBox.getInteger("Enter your 3rd number");
                if(g3 == g1){
                    g3 =iBox.getInteger("Number used, please re-enter");
                }
                else if(g3 == g2){
                    g3 =iBox.getInteger("Number used, please re-enter");
                }
            g4 = iBox.getInteger("Enter your 4th number");
                if(g4 == g1){
                    g4 =iBox.getInteger("Number used, please re-enter");
                }
                else if(g4 == g2){
                    g4 =iBox.getInteger("Number used, please re-enter");
                }
                else if(g4 == g3){
                    g4 =iBox.getInteger("Number used, please re-enter");
                }
            oBox.print(" " + g1 + " " + g2 + " " + g3 + " " + g4 + " ");

Answer 1

你应该使用循环和集合。伪代码：

let S be the set of used numbers(or array, if order is important)
clear contents of S
for I = 1 to N, where N is the number of numbers you want to get
    int g = iBox.getInteger("Enter Ith number");
    while(S.contains(g))
        g = iBox.getInteger("Number used, please re-enter");
    Add g into S.

Answer 2

选择ArrayList
扫描用户的值，解析，验证添加到ArrayList
执行contains()以检查list

Answer 3

我建议将以前的输入存储在List或某种集合中。然后，您可以使用.contains(Object o)方法查看集合是否已包含特定值。

这将允许您将应用程序扩展到固定数量的输入之外。

Collection API

用户输入，不允许两次相同的输入

3 个答案: