陣列

宣告陣列int[] array = null; array放在棧裡

建立陣列 array = new int[10]; 在堆中開闢區域

數組裡面是物件的例子：Man[] mans = {new Man();new Man()};

int[] a=new int[10];//一經建立便有了預設值0

for (int i : a) {//輸入a.for
  System.out.println(i);
}

int[]b=reverse(a);//此處不用再new
for (int i : b) {
  System.out.println(i);
}

二維陣列：int[][] array = {{1,2,3},{4,5,6},{7,8,9}};

int [][]a={{1,2,3},{4,5,6},{7,8,9}};
for (int i = 0; i < a.length; i++) {//注意length的用法
  for (int j = 0; j < a[i].length; j++) {
    System.out.println(a[i][j]);
   }
}
//增強迴圈輸出二位陣列
for (int[] ints : a) {//輸入a.for
  for (int anInt : ints) {//輸入ints.for
    System.out.println(anInt);
   }
}

System.out.println(Arrays.toString(a));//[67, 23, 54, 79, 1, 3, 75, 34]
Arrays.sort(a);
System.out.println(Arrays.toString(a));//[1, 3, 23, 34, 54, 67, 75, 79]
 

檢視JDK幫助文件：