//静态初始化
int[] numbers = new int[] { 3, 5, 12, 8, 7 };
String[] names = { "Miracle", "Miracle He" };//使用静态初始化的简化形式

//动态初始化
int[] numbers = new int[5];
String[] names = new String[2];

public class TestArray {public static void main(String[] args) {String[] names = new String[3];names[0] = "Miracle";names[1] = "Miracle He";//以下代码将输出Miracle Miracle He null/*for(int i = 0; i < names.length;i++) {System.out.print(names[i] + " ");}*///还可以使用foreach来遍历for(String name : names) {System.out.print(name + " ");}}
}

public class TestForEach {public static void main(String[] args) {int[] numbers = { 3, 5, 12, 8, 7 };for(int number : numbers) {int num = number * 10;System.out.print(num + ",");}System.out.println("");//numbers仍然未发生变化(如果换成for将改变)for(int i = 0;i < numbers.length;i++) {System.out.print(numbers[i] + ",");}}
}

public class TestArrayLength {public static void main(String[] args) {int[] numbers = { 3, 5, 12 };int[] digits = new int[4];System.out.println("digits数组长度：" + digits.length);//4for(int number : numbers) {System.out.print(number + ",");//3,5,12,
        }System.out.println("");for(int digit : digits) {System.out.print(digit + ",");//0,0,0,0,
        }System.out.println("");digits = numbers;System.out.println("digits数组长度：" + digits.length);//3
    }
}

public class TestPrimitiveArray {public static void main(String[] args) {//1.定义数组int[] numbers;//2.分配内存空间numbers = new int[4];//3.为数组元素指定值for(int i = 0;i < numbers.length;i++) {numbers[i] = i * 10;}}
}

class Person {public int age;public String name;public void display() {System.out.println(name + "的年龄是: " + age);}
}
public class TestReferenceArray {public static void main(String[] args) {//1.定义数组
        Person[] persons;//2.分配内存空间persons = new Person[2];//3.为数组元素指定值Person p1 = new Person();p1.age = 28;p1.name = "Miracle";Person p2 = new Person();p2.age = 30;p2.name = "Miracle He";persons[0] = p1;persons[1] = p2;//输出元素的值for(Person p : persons) {p.display();}}
}

谈到这里，不知是否有朋友要问：Java的多维数组是什么样的？我的回答是：可以有。为什么呢？从底层来看，数组元素可以存放引用类型，包含数组。也就是说在数组元素的内部还可以包含数组(如int[][] numbers = new int[length][])，也即二维数组可当作一维数组(数组长度为length)来处理，也可以同时指定多个维度的长度(如int[][] matrix = new int[length][width])，不过必须至少指定最左端的数组长度length。由此我们得出结论: 任何多维数组(维度为n，n>1)都当作一维数组，其数组元素为n-1维数组。