大家好！我的这段代码哪里错了．，我调试好久，提示没有主函数啊　？


class A {
A (){
System.out.println("????");
}

A(String s){
return this.s = "Hello Javas!!!";
}
}

public class Test {
static {
System.out.println("diyige jieguo!!1");
}

public static void main(String [] args){
new A( String s);

int a=2,b=3;

System.out.println(a+b+"zhi shi!"+a +b);
}
}

谢谢大家了

public static void main(String [] args){
new A( String s);//能这样定义吗？

int a=2,b=3;

System.out.println(a+b+"zhi shi!"+a +b);
}
}

class A {
        A (){
                System.out.println(\"????\");
        }
        
         A(String s){
            this.s =s;
        }
       String s;
    }

public class Test {
       static {
            System.out.println(\"diyige jieguo!!1\");
        }
     public static void main(String [] args){
         A a1=new A(\"hello java\");
         System.out.println(a1.s);
         A a2=new A();    
         int a=2,b=3;
        System.out.println(a+b+\"zhi shi!\"+a +b);
    }
}