我的java代码感觉没错啊，来个人看看哪里有问题

class Complex{
private double RealPart;
private double ImaginPart;
Complex(double r,double i){
this.RealPart=r;
this.ImaginPart=i;
}

public void setReal(double RealPart){
    this.RealPart=RealPart;
}

public void setImagin(double ImaginPart){
    this.ImaginPart=ImaginPart;
}

public double getReal(){
    return RealPart;
}

public double getImagin(){
    return ImaginPart;
}

public Complex complexAdd(Complex a){
    double real_1=a.getReal();
    double imagin_1=a.getImagin();
    double newReal=RealPart+real_1;
    double newImagin=ImaginPrat+a.getImagin();
    Complex result=new Complex(newReal,newImagin);
    return result;
}

public String toString(){
    if(newReal==0){
        if(newImagin==0){
            return '0';
        }
        else{
            return newImagin+'i';
        }
    }
    else{
        if(newImagin==0){
            return newReal;
        }
        else if(newImagin>0){
            return newReal+'+'+newImagin+'i';
        }
        else{
            return newReal+newImagin+'i';
        }
    }
}

}

public class complexDemo(){
public static void main(String[] args){
Complex a=new Complex();
Complex b=new Complex();

        a.setReal(2.0);
        a.setImagin(-2.0);
        b.setReal(1.0);
        c.setImagin(-1.0);
        complexAdd(a);
        System.out.println(toString());
}

}

public class complexDemo是个类，你后面加括号()干嘛。
把后面括号去掉，有帮助的话采纳一下哦！

public class complexDemo是个类，后面不需要加()