当我在java类中创建一个对象而不传递参数时它不起作用？

Question

public class Client {
    public static void main(String args[]){
        Malo e = new Malo();
        e.setEid(11);
        e.setEsalary(3000);
        e.setEname("durga");
        System.out.println(e);
}
}

当我创建一个对象并用点运算符传递参数时它不起作用。它说构造函数没有定义

public class Client {
    public static void main(String args[]){
       Malo e = new Malo(11,3000,"del");
       System.out.println(e);
}
}

但是当我将参数传递到对象创建行时它可以工作，但是为什么上述方法不起作用？

public class Malo {
        int eid;
        int esalary;
        String ename;
    
        //constructors
    
        public Malo(int eid, int esalary, String ename) {
            this.eid = eid;
            this.esalary = esalary;
            this.ename = ename;
        }
    
    
        public int getEid() {
            return this.eid;
        }
    
        public void setEid(int eid) {
            this.eid = eid;
        }
    
        public int getEsalary() {
            return this.esalary;
        }
    
        public void setEsalary(int esalary) {
            this.esalary = esalary;
        }
    
        public String getEname() {
            return this.ename;
        }
    
        public void setEname(String ename) {
            this.ename = ename;
        }
        
    
    
        @Override
        public String toString() {
            return "{" +
                " eid='" + getEid() + "'" +
                ", esalary='" + getEsalary() + "'" +
                ", ename='" + getEname() + "'" +
                "}";
        }
        
    }

这是我的 malo 课程，我宣布为公开的

Answer 1

因为你在 Malo 上没有零参数构造函数，或者如果你有它不是公开的。