Java中的動態定義數組

1.一維矩陣的動態定義(程式碼注釋)

1.1方法一

package dongtai;

import java.util.Scanner;
import java.util.ArrayList;

public class DongTai {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        ArrayList<Integer> p = new ArrayList<>();   //創建一個ArrayList
        int n = scan.nextInt();   
        for(int i=0; i<n+1; i++)  
        {
            p.add(0);     //往p數組裡面添加元素
        }
        for(int j=0; j<n+1; j++)  
        {
            p.set(j, scan.nextInt());  //鍵盤端輸入數組的元素大小
        }

 

 

1.2方法二(多維數組也可用這種方法)

package dongtai;

import java.util.Scanner;

public class DongTai {
    public static int []p;   //直接定義一個一維數組
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int num = scan.nextInt();
        p = new int[num];  //可直接定義數組大小
    }
}

 

 

2.二維數組

package dongtai;

import java.util.Scanner;

public class DongTai {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int [][] m;
        m = new int[n][];
        for(int i=1; i<n; i++)        //前兩個n位第一維,後兩個n為第二維
        {
            m[i] = new int[n];        //動態創建第二維
            for(int j=1; j<n; j++)
            {
                m[i][j] = 0;
            }
        }
    }
}

 

3.二維數組與多維數組(1.2方法二)

package dongtai;

import java.util.Scanner;

public class DongTai {
    public static int arr[][][]; 
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        arr = new int[n][n][n];
    }
}

 

Tags: