Question

我试图看看这里的问题是什么。基本上，在ctr = 10,100,1000和10000之后，程序应该从sumOfRand中减去sumOfCutoff，并从sumOfRand中减去sumOfRounded，然后打印两者。但由于某种原因，它不打印两行，或做正确的减法。问题的附加部分是正确的，但减法部分是我遇到麻烦的地方。

有人看错了什么吗？

    int ctr;
    for(ctr = 0; ctr <= 10000; ctr++);
    {
    Random rand = new Random();
    double A1 = rand.nextDouble();
    double A2 = Math.floor(A1 * 1e3) / 1e3;
    double A3 = (double)Math.round(A1* 1000) / 1000;
    double A4 = Math.floor(A1 * 1e4) / 1e4;
    double A5 = (double)Math.round(A1* 10000) / 10000;
    double A6 = Math.floor(A1 * 1e5) / 1e5;
    double A7 = (double)Math.round(A1* 100000) / 100000;
    double A8 = Math.floor(A1 * 1e6) / 1e6;
    double A9 = (double)Math.round(A1* 1000000) / 1000000;

    System.out.println("The accumlators are:");
    System.out.println(A1);
    System.out.println(A2);
    System.out.println(A3);
    System.out.println(A4);
    System.out.println(A5);
    System.out.println(A6);
    System.out.println(A7);
    System.out.println(A8);
    System.out.println(A9);
    System.out.println();

    double sumOfRand = (A1 + rand.nextDouble());
    double sumOfCutoff = (A2 + A4 + A6 + A8);
    double sumOfRounded = (A3 + A5 + A7 + A9);

    System.out.println("The residuals after the 10th time are:");       
    if(ctr == 10)
    System.out.println(sumOfRand - sumOfCutoff);
    System.out.println(sumOfRand - sumOfRounded);
    System.out.println();

    System.out.println("The residuals after the 100th time are:");
    if(ctr == 100)
    System.out.println(sumOfRand - sumOfCutoff);
    System.out.println(sumOfRand - sumOfRounded);
    System.out.println();

    System.out.println("The residuals after the 1000th time are:"); 
    if(ctr == 1000)
    System.out.println(sumOfRand - sumOfCutoff);
    System.out.println(sumOfRand - sumOfRounded);
    System.out.println();

    System.out.println("The residuals after the 10000th time are:");
    if(ctr == 10000)
    System.out.println(sumOfRand - sumOfCutoff);
    System.out.println(sumOfRand - sumOfRounded);
    }

}

编辑编辑编辑

    Random rand = new Random();
    double A1 = rand.nextDouble();
    double A2 = Math.floor(A1 * 1e3) / 1e3;
    double A3 = (double)Math.round(A1* 1000) / 1000;
    double A4 = Math.floor(A1 * 1e4) / 1e4;
    double A5 = (double)Math.round(A1* 10000) / 10000;
    double A6 = Math.floor(A1 * 1e5) / 1e5;
    double A7 = (double)Math.round(A1* 100000) / 100000;
    double A8 = Math.floor(A1 * 1e6) / 1e6;
    double A9 = (double)Math.round(A1* 1000000) / 1000000;

    System.out.println("The accumlators are:");
    System.out.println(A1);
    System.out.println(A2);
    System.out.println(A3);
    System.out.println(A4);
    System.out.println(A5);
    System.out.println(A6);
    System.out.println(A7);
    System.out.println(A8);
    System.out.println(A9);
    System.out.println();

    double sumOfRand = 0.0;
    double sumOfCutoff = 0.0;
    double sumOfRounded = 0.0;      

    int ctr;
    for(ctr = 0; ctr <= 10000; ctr++)
    {
        if (ctr == 10)
        {
            System.out.println("The residuals after the 10th time are:");   
            System.out.println("Cutoff:" + (sumOfRand - sumOfCutoff));
            System.out.println("Rounded:" + (sumOfRand - sumOfRounded));
            System.out.println();
        }

        if(ctr == 100)
        {
            System.out.println("The residuals after the 100th time are:");          
            System.out.println("Cutoff:" + (sumOfRand - sumOfCutoff));
            System.out.println("Rounded:" + (sumOfRand - sumOfRounded));
            System.out.println();
        }

        if(ctr == 1000)
        {
            System.out.println("The residuals after the 1000th time are:");             
            System.out.println("Cutoff:" + (sumOfRand - sumOfCutoff));
            System.out.println("Rounded:" + (sumOfRand - sumOfRounded));
            System.out.println();
        }

        if(ctr == 10000)
        {
            System.out.println("The residuals after the 10000th time are:");
            System.out.println("Cutoff:" + (sumOfRand - sumOfCutoff));
            System.out.println("Rounded:" + (sumOfRand - sumOfRounded));
        }
    }

}

}

Answer 1

错误＃01

您的{...}条件似乎缺少if，例如......

if(ctr == 10)
    System.out.println(sumOfRand - sumOfCutoff);
    System.out.println(sumOfRand - sumOfRounded);
    System.out.println();

实际上在说......

if(ctr == 10)
    System.out.println(sumOfRand - sumOfCutoff);

System.out.println(sumOfRand - sumOfRounded);
System.out.println();

我认为你的意思是

if(ctr == 10) {
    System.out.println(sumOfRand - sumOfCutoff);
    System.out.println(sumOfRand - sumOfRounded);
    System.out.println();
}

大括号为一组条件提供了背景......

这适用于所有if语句......

您也可以使用if-else语句代替......

if(ctr == 10) {
    //...
} else if(ctr == 100) {
    //...
} else if(ctr == 1000) {
    //...
} else if(ctr == 10000) {
    //...
}

错误＃2

for (ctr = 0; ctr <= 10000; ctr++);
{

如果您在for语句的末尾看起来很狡猾，那么您就拥有;。这基本上意味着，循环1000次，......什么都不做......

将其更改为...

for (ctr = 0; ctr <= 10000; ctr++)
{

删除声明末尾的;

减法打印错误

1 个答案:

错误＃01

错误＃2