JDK source code reading self-study notes ------- (g) (On a two-dimensional array)

• The actual development in general use up to two-dimensional array, no matter how high are rarely used
• Two-dimensional array rarely used, the actual development will be used instead of using container

1, create a two-dimensional array

1          // two-dimensional array initialization 
2          int [] [] = secondDimensional new new  int [. 3] [];

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2, a two-dimensional array assignment

1          // two-dimensional array Assignment 
2          secondDimensional [0] = new new  int [] {1, 2,. 3 };
 . 3  
. 4          secondDimensional [1] = new new  int [] {1, 2,. 3,. 4};

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3, operation of a two-dimensional array Tabular

• Thinking: the establishment of a one-dimensional array, one-dimensional array into a two-dimensional array to generate tables
• Note: [] a two-dimensional array is automatically generated no digital mapping
  
  

  1          // first data line 
  2          Object [] = {tablesName "ID", "name", "age", "functions", "entry date" };
   . 3  
  . 4          // user data 
  . 5          Object [] = {the userData 1001, "Joe Smith", 22 "teacher", "2010-11-21" };
   . 6  
  . 7          // two-dimensional array initialization 
  . 8          Object [] [] = secondDimensional new new Object [. 3 ] [];
   . 9  
  10          // stored data 
  . 11          secondDimensional [0] = tablesName;
   12 is  
  13 is          secondDimensional [. 1] = the userData;
  14  
  15          // print data 
  16         System.out.println("表格" + Arrays.toString(secondDimensional[0]));
  17         
  18         System.out.println("NUM" + Arrays.toString(secondDimensional[1]));

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