限制 Java 中的输入行数？

Question

我有一个问题，我想从用户那里获取输入，用户可以插入 1 行，最多 8 行，每行代表一个案例。我想要的是当用户插入 8 行时停止扫描器，或者如果用户想要少于 8 行，他可以按回车键或特定键来结束循环。

到目前为止我做了什么：

public static void doSomthing(){

    Scanner input = new Scanner(System.in);

    while (input.hasNextLine()) { // here I want to check so that it don't exeed 8 lines
        int e;
        int m;
        i = input.nextInt();
        j = input.nextInt();

        int num = 0;


        while (i != 0 || j != 0) {
            num += 1;
            e = (e + 1) % 100;
            m = (m + 1) % 400;
        }

        System.out.println(num);
    }

}

每行输入两个数字，一个代表i，一个代表j。

输入：

输出应该是：

C1: 0 
C2: 100
C3: 1
C4: 200

希望这能解释我的问题。

提前致谢！

Answer 1

正如@Abhishek 所建议的，您可以使用计数器变量：

public static void doSomthing(){
    Scanner input = new Scanner(System.in);
    int linesParsed = 0;
    while (linesParsed < 8 && input.hasNextLine()) {
        // What are you using these variables for? You compute their
        //  values, but then you do not use them
        int e;
        int m;
       // Where are these variables declared? It seems weird to have
        //  instance variables be named i and j
        i = input.nextInt();
        j = input.nextInt();

        int num = 0;
       
        // Unless i and j are being modified concurrently somewhere
        // else in the code, this will result in an infinite loop
        while (i != 0 || j != 0) {
            num += 1;
            e = (e + 1) % 100;
            m = (m + 1) % 400;
        }

        System.out.println(num);
        linesParsed++;
    }
}

限制 Java 中的输入行数？

Limit number of input lines in Java?

java

user-input

java.util.scanner