全局变量（或者属性）的初始化问题

public class Test {
    int a = 1;//静态初始化基本数据类型

    String[] s = {"Hello","World","你好，世界"};//静态初始化引用类型数组
    Example[] e = {new Example(2019,"小明"),new Example(2018,"小红")};

}
class Example{
    int id;
    String name;

    public Example(int id, String name) {
        this.id = id;
        this.name = name;
    }
}

public class Test02 {
    int a;
    String[] s;
    Example[] e = new Example[2];
    public void se(){
        a = 1;//动态初始化，必须在方法中，进行
        e[0] = new Example(2019,"小明");//同理，数组的动态初始化也必须在方法中进行，静态方法或者动态方法均可
        e[1] = new Example(2018,"小红")
    }
}
class Example{
    int id;
    String name;

    public Example(int id, String name) {
        this.id = id;
        this.name = name;
    }
}

public class Test03 {
    int a;
    a = 1;//直接对全局变量（即属性），先定义，接着初始化，这是错误的
    String[] s;
    s = {"ab","cd","ef"};
    Example[] e = new Example[2];
    e[0] = new Example(2019,"小明");//同理，数组也不能这样初始化操作
    e[1] = new Example(2018,"小红");
}
class Example{
    int id;
    String name;

    public Example(int id, String name) {
        this.id = id;
        this.name = name;
    }
}