在Java中将for循环转换为while循环 [英] Converting for loop to while loop in Java

问题描述

我需要将此for循环转换为while循环，以便我可以避免使用中断。

I need to convert this for loop into a while loop so I can avoid using a break.

double[] array = new double[100];

Scanner scan = new Scanner(System.in); 

for (int index = 0; index < array.length; index++)
    {
        System.out.print("Sample " + (index+1) + ": ");
        double x = scan.nextDouble();
        count++;
        if (x < 0) 
        {
            count--;
            break;
        }
        array[index] = x; 
    }

这是我想出来的，但我得到了不同的输出：

This is what I came up with but I'm getting a different output:

int index = 0;

double x = 0; 

while (index < array.length && x >= 0)
    {
        System.out.print("Sample " + (index+1) + ": ");
        x = scan.nextDouble();
        count++;
        if (x < 0) 
        {
            count--;
        }
        array[index] = x;
        index++;
    }

推荐答案

此解决方案提供相同的输出作为for循环：

this solution gives the same output as the for loop:

while (index < array.length && x >= 0)
{
    System.out.print("Sample " + (index+1) + ": ");
    x = scan.nextDouble();
    count++;
    if (x < 0) 
    {
        count--;
    }
    else
    {
        array[index] = x;
        index++;
    }
}

说明：

在for循环中使用break语句，因此在程序到达中断后没有任何反应。所以 array [index] = x; 没有被执行。

On the for loop you use the break statement so nothing happens after the program hits the break. So array[index] = x; didn't get executed.

在while循环中因为没有中断，循环继续，所以语句 array [index] = x; 和 index ++; 已执行。

On the while loop since there's no break, the loop continues, so the statements array[index] = x; and index++; got executed.

这就是你得到不同结果的原因。如果你不想要陈述

That's why you got different results. If you don't want the statements

array[index] = x;
index++; 

要执行，您只需将if语句设为if / else语句，如上所述。

To be executed you can simply make your if statement a if/else statement as above.

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