一:

int[] arr1 = new int[1];   //必须初始化数量,还有不初始化数字的

arr1[0] = 1;

  System.out.println("array1: " + Arrays.toString(arr1));

二:

int[] arr2 = {1,2};

System.out.println("array2: " + Arrays.toString(arr2));

三:

  int[] arr3 = new int[]{1,2};  //这个一定不能初始化数字

  System.out.println("array3: " + Arrays.toString(arr3));

输出结果:

array1: [1]
array2: [1, 2]
array3: [1, 2]

注:Integer[] 跟int[] 不同,不能转换