Question

 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了如何填充2D数组，我的问题是在嵌套for循环中，因为我增加到1它是否保持为1直到j被计数7次然后递增1，或者它们是否同时递增？

Answer 1

将它们视为堆栈。从外部循环开始，你把它放在堆栈中执行然后进入内部，这样最深层次的循环将位于顶部。你必须完成最顶层元素或最深层循环的工作然后它在它下面循环。这只是这种情况的类比。希望你明白了。

Answer 2

作为j的内部循环继续正好运行多次，直到达到满足＆＃39; j＆lt; DailyTemperature [0]。长度＆＃39;然后另一个循环继续进行进一步的迭代。

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( );

            }

Answer 3

它是否保持为1，直到j被计数7次然后递增1

是的，但更确切地说，它从0开始，因此它保持为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语句来轻松验证这一点：

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

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

如何填充2D多维数组？

3 个答案: