Question

作为初学者和java，我的代码输出有问题。代码仅为运行代码时输入的值打印“a”，“b”和“c”的值。我如何修改它以打印所有值，包括我在运行代码时所使用的值有人可以帮忙吗？谢谢！

class Numbers
{
    public static void main (String[] args)
    {
    for ( int i = 0; i < args.length; i++)
        {
        int a = Integer.parseInt(args[i]);
        System.out.print(a);
        int b = (a*a);  
        int c = (a*a*a);
        System.out.print(b);
        System.out.print(c);
        }       
    }
}

Answer 1

循环只运行一次，因为你的参数是3.所以args.length是1.这就是打印3,9和27的原因。

要使循环运行三次，您可以将String作为args[0]评估为int。在这种情况下，你需要类似的东西（这里没有异常处理）：

int numLoops = Integer.parseInt(args[0]);
for ( int i = 0; i < numLoops; i++)
        System.out.print(i);
        System.out.print(i*i);
        System.out.println(i*i*i);
}

Answer 2

So did I get it right in your comment? You want to pass a number that tells you how many iterations the loop should run. And for any iteration you want to write a incrementing number, its square and its cube?

class Numbers {
    public static void main (String[] args) {
        if (args.length == 0) {
            System.out.println("Please specify number.");
            return;
        }
        int iterationCount = Integer.parseInt(args[0]);
        for ( int i = 0; i < iterationCount; i++) {
            int a = i;
            System.out.print(a);
            int b = (a*a);  
            int c = (a*a*a);
            System.out.print(b);
            System.out.print(c);
        }       
    }
}

Answer 3

Please try this

javac Numbers.java
java Numbers 1 2 3

This should work. In first iteration of your for loop, the a variable will be 1, so it will print 1, 1 and 1. In second iteration, your a variable will be 2, so it will print 2, 4 and 8 and in your third iteration, your a variable will be 3, so it will print 3, 9 and 27.

Java - 不打印我想要的东西？

3 个答案: