如何填充二维多维数组？答案

【问题标题】：How are 2D Multidimensional arrays populated?如何填充二维多维数组？
【发布时间】：2018-01-27 18:58:35
【问题描述】：

 Scanner scan = new Scanner(System.in);

      double [][] DailyTemperature;

        double totalTracker = 0.0;
        String [] daysofweek = { "Monday ","Tuesday ","Wednsday ","Thursday","Friday ","Saturday ","Sunday "};

        DailyTemperature = new double[4][7];

        for ( int i = 0; i < DailyTemperature.length; i++ )
           for ( int j = 0; j < DailyTemperature[0].length; j++ )
            {
                System.out.print( "Enter " + daysofweek[j]+ "Temperature for week" + ( i + 1 ) + "\t");
                DailyTemperature[i][j] = scan.nextDouble( );

            }

所以这个问题只是确认二维数组是如何填充的，我的问题是在嵌套的 for 循环中，因为 i 增加到 1 它是否保持为 1 直到 j 被计数 7 次然后增加 1，或者它们同时增加?

【问题讨论】：

标签： java arrays for-loop multidimensional-array

【解决方案1】：

只需将它们视为堆栈即可。从外部循环开始，您将其放入堆栈执行然后进入内部，因此最深级别的循环将位于顶部。你必须完成最顶层元素或最深层循环的工作，然后它会在它下面循环。这只是本案例的类比。

【讨论】：

【解决方案2】：

j 的内部循环继续运行精确的次数，直到达到满足'j

for ( int i = 0; i < DailyTemperature.length; i++ )//executes firstly once
           for ( int j = 0; j < DailyTemperature[0].length; j++ )// continues execution until j < DailyTemperature[0].length.
            {
                System.out.print( "Enter " + daysofweek[j]+ "Temperature for week" + ( i + 1 ) + "\t");
                DailyTemperature[i][j] = scan.nextDouble( );

            }

【讨论】：

【解决方案3】：

它是否保持为 1 直到 j 被计数 7 次然后递增 1

是的，但更准确地说，它从 0 开始，所以它保持为 0，然后递增 1。

事实上，您可以通过在提示输入之前放置此 println 语句来非常轻松地验证这一点：

                System.out.println("i is now " + i + ", and j is now " + j);

还有输出：

i is now 0, and j is now 0
Enter Monday Temperature for week1  100

i is now 0, and j is now 1
Enter Tuesday Temperature for week1 200

i is now 0, and j is now 2
Enter Wednsday Temperature for week1    300

.
.
.


i is now 0, and j is now 6
Enter Sunday Temperature for week1  700

i is now 1, and j is now 0
Enter Monday Temperature for week2  800

i is now 1, and j is now 1
Enter Tuesday Temperature for week2

【讨论】：