jmu-Java-02 basic dynamic array syntax -04-

topic:

The input n, n row print multiplication tables.
You need to use each two-dimensional array of strings stored multiplication tables, such as storage 1*1=1.
In order to ensure that procedures used in the two-dimensional array, to be used after printing the multiplication tables Arrays.deepToStringcontent to print a two-dimensional array.

Reminder: output format may be used String.formator System.out.printf.

Output Format Description

1. Each end of the line with no spaces.
2. Between each of the expression (counting from the first character of an expression between the first character of the next expression), a total of 7 characters. As 2*1=2 2*2=4from the first to the second one 2 `2*2=4among the first letter, a total of seven characters (including spaces, in this example contains two spaces).

Sample input:

2
5

Sample output:

1*1=1
2*1=2  2*2=4
[[1*1=1], [2*1=2, 2*2=4]]
1*1=1
2*1=2  2*2=4
3*1=3  3*2=6  3*3=9
4*1=4  4*2=8  4*3=12 4*4=16
5*1=5  5*2=10 5*3=15 5*4=20 5*5=25
[[1*1=1], [2*1=2, 2*2=4], [3*1=3, 3*2=6, 3*3=9], [4*1=4, 4*2=8, 4*3=12, 4*4=16], [5*1=5, 5*2=10, 5*3=15, 5*4=20, 5*5=25]]


代码:

 1 import java.util.Scanner;
 2 import java.util.Arrays;
 3 public class Main {
 4     public static void main(String[] args) {
 5         Scanner sc = new Scanner(System.in);
 6         while(sc.hasNextInt()) {
 7             int n = sc.nextInt();
 8             String[][] arr = new String[n][];
 9             for(int i = 0;i < n;i++) {
10                 arr[i] = new String[i+1];
11                 for(int j = 0;j < i+1;j++) {
12                    arr[i][j] = (i+1)+"*"+(j+1)+"="+(i+1)*(j+1);
13                     if(j<i)
14                         System.out.printf("%-7s",arr[i][j]);
15                     else if(j==i)
16                         System.out.printf("%s",arr[i][j]);
17                 }
18                 System.out.println();
29             }
20             System.out.println(Arrays.deepToString(arr));
21         }
22     }
23 }

笔记:

1.格式限定每个表达式之间包含7个字符，因此想到了格式化输出，用“%-7s”控制字符串占七个字符位，负号表示左对齐
2.动态创建二维数组：
　　　　int [ ] [ ] ARR ; 
　　　　 ARR = new new int [a dimension ] [ ] ; // dynamically creating a first dimension 
　　　　 for (I = 0 ; I <a dimension ; I ++ ) { 
 　　　　　　ARR [I ] = new new int [number-D ] ; // dynamically create a second dimension 
　　　　 　　for (J = 0 ; J <dimensional number ; J ++ ) { 
　　　　　　 　　ARR [I ] [J ]= j; 
　　　　　　　}
　　　　　}