基础题,请进
wwss123456

------解决方案--------------------
lianxi t=new lianxi();
lianxi.Dec dec=t.new Dec();
内部类创建错了~
------解决方案--------------------
public class lianxi {
public static void main(String[] args){
double d=1.23;
lianxi b1 = new lianxi();
Dec dec= b1.new Dec();
dec.decrement(d);
System.out.println(d);
}
class Dec{
public Dec(){};
public double decrement(double d){
return d=d-1;
}


}
就没了，输出：
1.23

} 

------解决方案--------------------
public class lianxi {
public static void main(String[] args){
double d=1.23;
lianxi b1 = new lianxi();
Dec dec= b1.new Dec();
dec.decrement(d);
System.out.println(d);
}
class Dec{
public Dec(){};
public double decrement(double d){
return d=d-1;
}


}

}
------解决方案--------------------

Java code

public class lianxi {
    public static void main(String[] args) {
        double d = 1.23;
        lianxi l = new lianxi();//先实例一个lianxi对象
        Dec dec = l.new Dec();
        dec.decrement(d);
        System.out.println(d);
    }

    class Dec {
        public Dec() {
        }

        public double decrement(double d) {
            return d = d - 1;
        }

    }

}