Java二维数组的内存结构图:
今天看了个视频,说Java中二维数组是这样的:java中的二位数组是按维存储的。
在Java中是可以这样的,二维数组有三种定义格式!
定义格式1:
定义格式1的内存图:
定义格式2:
定义格式2的内存结构图:
定义格式3:
定义格式3内存图:
C语言二维数组的内存结构图:
突然,感觉和自己脑海中C的不一样。还专门去看了下C的。
void main()
{
int a[3][2];
cout << a <<"\t"<< &a << endl<<endl;
cout << a[0] << "\t" << a[1] << "\t" << a[2] << endl << endl;
cout << &a[0][0] << "\t" << &a[0][1] << endl << endl;
cout << &a[1][0] << "\t" << &a[1][1] << endl << endl;
cout << &a[2][0] << "\t" << &a[2][1] << endl << endl;
}
运行结果:
也就是说,C语言的二维数组确实是下面这样:,C语言的二维数组是连续一维存储的。
再详细看一下:
#include<iostream>
using namespace std;
void main()
{
int a[3][3] = { 1, 5, 9, 15, 28, 44, 65, 88, 99 };
cout << "各元素:" << endl;
cout << a[0][0] << " " << a[0][1] << " " << a[0][2] << " " << endl;
cout << a[1][0] << " " << a[1][1] << " " << a[1][2] << " " << endl;
cout << a[2][0] << " " << a[2][1] << " " << a[2][2] << " " << endl;
cout << "\n各元素地址:" << endl;
cout << &a[0][0] << " " << &a[0][1] << " " << &a[0][2] << " " << endl;
cout << &a[1][0] << " " << &a[1][1] << " " << &a[1][2] << " " << endl;
cout << &a[2][0] << " " << &a[2][1] << " " << &a[2][2] << " " << endl;
cout << "\na[0]:" << a[0] << " &a[0][0]: " << &a[0][0] << endl; //a[0] <==> &a[0][0]
cout << "a[1]:" << a[1] << " &a[1][0]: " << &a[1][0] << endl; //a[1] <==> &a[1][0]
cout << "a[2]:" << a[2] << " &a[2][0]: " << &a[2][0] << endl; //a[2] <==> &a[2][0]
cout << "\na[0]+1:" << a[0]+1 << " &a[0][1]:" << &a[0][1] << endl; //a[0]+1 <==> &a[0][1]
cout << "a[1]+1:" << a[1]+1 << " &a[1][1]:" << &a[1][1] << endl; //a[1]+1 <==> &a[1][1]
cout << "a[2]+1:" << a[2]+1 << " &a[2][1]:" << &a[2][1] << endl; //a[2]+1 <==> &a[2][1]
cout << "\n&a:" << &a << endl; //&a:数组的首地址
cout << "&a +1:" << &a + 1 << endl; //注意步长:直接跳了一个二维数组
cout << "\na+0:" << a << endl; //第0行的首地址
cout << "a+1:" << a + 1 << endl; //第1行的首地址
cout << "a+2:" << a + 2 << endl; //第2行的首地址
cout << endl;
cout << "(*a)[2]:" << (*a)[2] << endl;
cout << "(*a +1)[2]:" << (*a + 1)[2] << endl;
cout << "*a[2]:" << *a[2] << endl;
cout << endl;
cout << "*a:" << *a << endl;
cout << "*(a+1):" << *(a + 1) << endl;
cout << "*(a + 1) + 2:" << *(a + 1) + 2 << endl;
cout << "*(*(a+1)+2):" << *(*(a + 1) + 2) << endl;
}
附录:
java二维数组的遍历:
public class Main {
public static void main(String[] args) {
int[][] arr = { { 1, 2, 3 }, { 4, 5 }, { 6 } };
for (int row = 0; row < arr.length; row++) { // 外层循环:二维数组的长度,也就是一维数组的个数
for (int col = 0; col < arr[row].length; col++) { // 内层循环:某一维数组的长度
System.out.print(arr[row][col] + " ");
}
System.out.println();
}
}
}
打印结果:
1 2 3
4 5
6