变量顺序

package example;


public class Test  {
    
  //编译失败，非法前向引用
        int num1=num2+1;
        int num2=10;
   

}

package example;


public class Test  {
    
    
        //编译通过
        int num1=num2+1;
        static int num2=10;
    

}

package example;


public class Test  {
    
     //编译失败，非法前向引用
        static int num1=num2+1;
        static int num2=10;
    

}

要考虑到静态字段的加载是随着类创建诞生