Initialization and basic operation examples of two-dimensional arrays in Java programming _java

Declaration and initialization of Java two-dimensional arrays

1. A two-D array can be regarded as an array of elements of an array;
The Declaration and initialization of two-dimensional arrays in 2.Java should be carried out in order from high to low dimensions.

Instance:
Static initialization:
Array2.java:

Program code

public class Array2 
{public 
  static void Main (String args[]) { 
    int a[][] = {{1,2},{3,4,5,6},{7,8,9}}; 
    for (int i=0 i <a.length; i++) {for 
      (int j=0; j<a[i].length; j + +) { 
        System.out.println ("a[" + i + "] [" + J + "]=" + A[i][j]);}}} 
 

Dynamic initialization:

Program code

public class Array2D 
{public 
  static void Main (String args[]) { 
    int i, J; 
    String s[][]; 
    s = new string[3][]; 
    S[0] = new string[2]; 
    S[1] = new String[3]; 
    S[2] = new string[2]; 
    for (i=0 i<s.length; i++) { 
      for (j=0 J <s[i].length; j + +) { 
        S[i][j] = new String ("My position is:" + i + "," + j); 
      } 
    for (i=0 i<s.length; i++) {for 
      (j=0; j<s[i].length; j +) { 
        System.out.println (s[i][j)); 
    } 
  } 
} 

About two-dimensional array operations in Java [instance]:

public class lesson{public static void Main (String [] args) {//two-D array declaration mode://data type [] [] Array name = new data type [ 
    Length] [length]; 
     
    The data type [] [] Array name = {{123},{456}}; /* int [] [] arr = {{123},{456}}; A two-dimensional array with two rows of three columns defined and assigned for (int x = 0; x<arr.length; x + +) {//Locate line for (int y = 0; y<arr[x].length; y++) {//Locate each line 
      Number of elements System.out.print (Arr[x][y]); 
    } System.out.println ("n"); } */int [] num = new int [3][3]; Two-dimensional array num[0][0 with three rows and three columns defined] = 1; Assign a value to the first element of the first line num[0][1] = 2; Assign a value to the second element in the first row num[0][2] = 3; Assign a value to the third element in the first row num[1][0] = 4; Assign a value to the first element of the second line num[1][1] = 5; Assign the second element to the second row num[1][2] = 6; Assign a value to the third element of the second line num[2][0] = 7; Assign a value to the first element of the third line num[2][1] = 8; Assign a value to the second element of the third row num[2][2] = 9;  
        Assign a third row to the third element for (int x = 0; x<num.length; x + +) {//Locate line for (int y = 0; y<num[x].length; y++) {//Locate the number of elements per row 
      System.out.print (Num[x][y]); } System.out.println ("n"); 
    }}//array value Arr[x][y] represents the value specified in column y of line X. When using a two-dimensional array object, note the length represented by length, and/or the array name, followed by a direct length (such as Arr.length), which refers to a few rows (row);//Specify the index followed by length (such as Arr[0].length), 

 Refers to the element that the row owns, that is, the number of columns (column).

Take another example: two two-dimensional arrays, incorporating them into a new two-dimensional array, with elements of two array corresponding elements. Input two array: {{1,5},{2,3},{6,5}},   {4,2},{2,6},{5,7}}
Output print: {{5,7},{4,9},{11,12}}}

 code: class arraysctrl{static void Arraysadd (int[][] a,int[][] b) {StringBuffer Sbre 
    Sult = new StringBuffer ("{"); 
    Int[][] result = new Int[a.length][b.length]; 
      for (int i=0;i<a.length;++i) {sbresult.append ("{"); 
        for (int j=0;j<a[i].length;++j) {Result[i][j] = a[i][j]+b[i][j]; 
        Sbresult.append (Result[i][j]); 
          if (j = = a[i].length-1) {if (i = = a.length-1) {sbresult.append ("}"); 
          }else{sbresult.append ("},"); 
        } break; 
      } sbresult.append (","); 
        } if (i = = a.length-1) {sbresult.append ("}"); 
      Break 
  } System.out.println (Sbresult); 
    public static void Main (string[] args) {int[][] ATst1 = {{1,5},{2,3},{6,5}}, ATst2 = {{4,2},{2,6},{5,7}}; 
  Arraysadd (ATST1,ATST2); } 
}