关于#java#的问题：三个参数构造方法四个参数的构造方法 getter、setter方法info()方法返回对象信息，(返回值类型:String)

请大神教一教

定义Emp员工类
属性:
eno(String) 工号
name(string) 姓名
age(string) 年龄
sal(double) 薪资
address(string) 住址

想用无参数构造

三个参数构造方法四个参数的构造方法 getter、setter方法
info()方法返回对象信息，(返回值类型:String)

在主方法中实例化三个对象，分别调用三个构造方法实例化对象，没有赋值的属性，使用seter方法来赋值。最后显示每个对象的信息。

public class Emp {
    private String eno;
    private String name;
    private String age;
    private double sal;
    private String address;

    public Emp() {
    }

    public Emp(String eno, String name, String age) {
        this.eno = eno;
        this.name = name;
        this.age = age;
    }

    public Emp(String eno, String name, String age, double sal) {
        this.eno = eno;
        this.name = name;
        this.age = age;
        this.sal = sal;
    }

    public String info() {
        return "工号:" + this.eno + " 姓名:" + this.name + " 年龄:" + this.age + " 薪资:" + this.sal + " 住址:" + this.address;
    }

    public String getEno() {
        return eno;
    }

    public void setEno(String eno) {
        this.eno = eno;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public double getSal() {
        return sal;
    }

    public void setSal(double sal) {
        this.sal = sal;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public static void main(String[] args) {
        final Emp emp1 = new Emp();
        emp1.setEno("1");
        emp1.setName("1");
        emp1.setAge("1");
        emp1.setSal(1.0);
        emp1.setAddress("1");
        final Emp emp2 = new Emp("2", "2", "2");
        emp2.setSal(2.0);
        emp2.setAddress("2");
        final Emp emp3 = new Emp("3", "3", "3", 3.0);
        emp3.setAddress("3");
        System.out.println(emp1.info());
        System.out.println(emp2.info());
        System.out.println(emp3.info());
    }
}

举个例子吧～你想构造函数初始化哪3个属性

public class Emp {

    private String eno;
    private String name;
    private String age;
    private double sal;
    private String address;
    
    //无参构造
    public Emp() {
        super();
    }
    
    //三参构造
    public Emp(String eno, String name, double sal) {
        super();
        this.eno = eno;
        this.name = name;
        this.sal = sal;
    }

    //四参构造
    public Emp(String eno, String name, String age, double sal) {
        super();
        this.eno = eno;
        this.name = name;
        this.age = age;
        this.sal = sal;
    }

    public String getEno() {
        return eno;
    }
    public void setEno(String eno) {
        this.eno = eno;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAge() {
        return age;
    }
    public void setAge(String age) {
        this.age = age;
    }
    public double getSal() {
        return sal;
    }
    public void setSal(double sal) {
        this.sal = sal;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }

    //info返回对象信息
    public String info() {
        return "Emp [eno=" + eno + ", name=" + name + ", age=" + age + ", sal=" + sal + ", address=" + address + "]";
    }
    
}

public class Test {
    
    public static void main(String args[]) {
        Emp e1 = new Emp();
        e1.setEno("1001");
        e1.setName("Bob");
        e1.setAge("25");
        e1.setSal(8000);
        e1.setAddress("重庆市麻辣街道麻辣小区");
        System.out.println(e1.info());
        Emp e2 = new Emp("1002", "Tom", 5000.0);
        e2.setAge("23");
        e2.setAddress("北京市花园路花园小区");
        System.out.println(e2.info());
        Emp e3 = new Emp("1003", "Tom", "22", 5000.0);
        e3.setAddress("上海市黄浦区外滩小区");
        System.out.println(e3.info());
        
        
    }

}

package test6;

public class Emp {
    String eno;
    String name;
    String age;
    double sal;
    String address;

    public Emp() {
    }

    public Emp(String eno, String name, String age, double sal, String address) {
        this.eno = eno;
        this.name = name;
        this.age = age;
        this.sal = sal;
        this.address = address;
    }

    /**
     * 获取
     * @return eno
     */
    public String getEno() {
        return eno;
    }

    /**
     * 设置
     * @param eno
     */
    public void setEno(String eno) {
        this.eno = eno;
    }

    /**
     * 获取
     * @return name
     */
    public String getName() {
        return name;
    }

    /**
     * 设置
     * @param name
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * 获取
     * @return age
     */
    public String getAge() {
        return age;
    }

    /**
     * 设置
     * @param age
     */
    public void setAge(String age) {
        this.age = age;
    }

    /**
     * 获取
     * @return sal
     */
    public double getSal() {
        return sal;
    }

    /**
     * 设置
     * @param sal
     */
    public void setSal(double sal) {
        this.sal = sal;
    }

    /**
     * 获取
     * @return address
     */
    public String getAddress() {
        return address;
    }

    /**
     * 设置
     * @param address
     */
    public void setAddress(String address) {
        this.address = address;
    }

    public String toString() {
        return "Emp{eno = " + eno + ", name = " + name + ", age = " + age + ", sal = " + sal + ", address = " + address + "}";
    }
}