Java程序将编译，但不会在命令提示符下运行 公共类ProjectOne { 公共静态void main（字符串[]args） { int i，count1=0，count2=0，count3=0； int sum1=0，sum2=0，sum3=0，总计； 对于（i=1；i

您正在重置

for

循环中的

i

变量，使其永不结束。请尝试此修改后的代码：

public class ProjectOne
{
    public static void main (String[] args)
    {
        int i, count1 = 0, count2 = 0, count3 = 0;
        int sum1 = 0, sum2 = 0, sum3 = 0, total;

        for(i=1; i<1000; ++i) //creates loop that will iterate for every number
        {
            if (i%3 == 0)

                count1 += 1; //gathers total #'s <1000 that can be divided by 3

            if (i%5 == 0)

                count2 += 1; //same as above, but divisible by 5

            if (i%3 == 0 && i%5 ==0)

                count3 += 1; //gathers count for where sets intersect

            for (i=1; i<=count1; ++i)

                sum1 += 3*i; //creates sum for all multiples of 3

            for (i=1; i<=count2; ++i)

                sum2 += 5*i; //creates sum for all multiples of 5

            for (i=1; i<= count3; ++i)

                sum3 += 15*i; //creates sum for where sets intersect

        }

        total = (sum1 + sum2) - sum3; //totals two sums while subtracting
                                        //the intersections that would double
        System.out.print (total); // prints total value
    }
}

公共类ProjectOne
{
公共静态void main（字符串[]args）
{
int i，count1=0，count2=0，count3=0；
int sum1=0，sum2=0，sum3=0，总计；
对于（i=1；i您没有遗漏任何关于命令提示符的内容。您已经创建了一个无限循环-您的程序正在一次又一次地做同样的事情

回想一下，在Java（和C，以及许多使用C派生语法的语言）中，类似这样的
for
循环：

public class ProjectOne
{
    public static void main (String[] args)
    {
        int i, count1 = 0, count2 = 0, count3 = 0;
        int sum1 = 0, sum2 = 0, sum3 = 0, total;

        for(i=1; i<1000; ++i) //creates loop that will iterate for every number
        {
            if (i%3 == 0)

                count1 += 1; //gathers total #'s <1000 that can be divided by 3

            if (i%5 == 0)

                count2 += 1; //same as above, but divisible by 5

            if (i%3 == 0 && i%5 ==0)

                count3 += 1; //gathers count for where sets intersect

            for (int j=1; j<=count1; ++j)

                sum1 += 3*j; //creates sum for all multiples of 3

            for (int j=1; j<=count2; ++j)

                sum2 += 5*j; //creates sum for all multiples of 5

            for (int j=1; j<= count3; ++j)

                sum3 += 15*j; //creates sum for where sets intersect

        }

        total = (sum1 + sum2) - sum3; //totals two sums while subtracting
                                        //the intersections that would double
        System.out.print (total); // prints total value
    }
}

请注意，我已将
I
更改为
j
（并在每个循环中声明了
j
；这样每个循环都会得到一个名为
j
的单独变量，但如果需要，您可以在
main
的开头声明一次，并且不会有任何区别）

您的程序仍然无法正常工作（它将给您错误的答案），但这将修复您所问的无限循环。
您是如何从命令提示符编译和运行此程序的？哎呀。您正在同时修改循环中的
i
。在每次循环迭代结束时，
i=count3+1
。是的@Elliott Frisch您写的，这就是我提供正确和修改答案的原因.我把内部循环中的i改为j，使循环无限大，现在循环不再处于无限状态。上面的程序将把这个77777614作为输出返回。
for (i=1; i<= count3; ++i)
    sum3 += 15*i; //creates sum for where sets intersect

i=1;
while(i <= count3)
{
    sum3 += 15*i; //creates sum for where sets intersect
    ++i;
}

i=1;
while(i<1000)
{
    if (i%3 == 0)
        count1 += 1;

    if (i%5 == 0)
        count2 += 1;

    if (i%3 == 0 && i%5 ==0)
        count3 += 1;

    i=1;
    while(i <= count1)
    {
        sum1 += 3*i;
        ++i;
    }

    i=1;
    while(i <= count2)
    {
        sum1 += 5*i;
        ++i;
    }

    i=1;
    while(i <= count3)
    {
        sum1 += 15*i;
        ++i;
    }

    // HERE

    ++i;
}

for (int j=1; j<=count1; ++j)
    sum1 += 3*j; //creates sum for all multiples of 3

for (int j=1; j<=count2; ++j)
    sum2 += 5*j; //creates sum for all multiples of 5

for (int j=1; j<= count3; ++j)
    sum3 += 15*j; //creates sum for where sets intersect