Question

我是Java的新手，我有一个可能很简单的问题。

我有这段代码：

public class Person {
    String name;
    int age;
    boolean isMan;

    Person(String nameParam,int ageParam,boolean isManParam) {
        this.name = nameParam;
        this.age = ageParam;
        this.isMan = isManParam;
    }
}

在另一个demoClass中，我初始化了类Person的对象：

public class toStringDemo {
    public static void main(String[] args) {
       Person human = new Person("Jack",28,true);
    }
}

我有一个任务是使用toString（）方法编写方法showPersonInfo（）显示初始化对象的所有三个字段。任何帮助？

Answer 1

每个Java类始终存在toString方法。但是如果你没有覆盖它来指定要返回的内容，它将默认返回＆＃34; 类名，然后是'at'符号，最后是hashCode ＆＃34;，类似于Person@19821f。更多信息here。

所以你应该覆盖toString这样的Person方法（确实改变结果String）：

@Override
public String toString() {
      String s = name +", age "+age+", isMan: "+isMan;
      return s;
}

然后要显示此内容，请创建showPersonInfo方法：

public void showPersonInfo(){

   System.out.println(this.toString()); // OR
   // System.out.println(this); // Java prints the toString method by default

}

Answer 2

public class Person {

String name;
int age;
boolean isMan;


Person(String nameParam,int ageParam,boolean isManParam){
    this.name = nameParam;
    this.age = ageParam;
    this.isMan = isManParam;
     }
}

@Override
public String toString() {
    return "name:" + this.name + ", age:" + this.age + ", isMan:" + this.isMan ;
}

public void showPersonInfo {
    System.out.println(toString());
}

Answer 3

public class Person {
    String name;
    int age;
    boolean isMan;

    Person(String nameParam,int ageParam,boolean isManParam) {
        this.name = nameParam;
        this.age = ageParam;
        this.isMan = isManParam;
    }

    @Override
    public String toString() {
        return "Name: " + this.name +
               "\nAge: " + this.age +
               "\nIs a Man?: " + this.isMan;
    }

    public String showPersonInfo() {
        return this.toString();
    }
}

在您的主要方法中：

public class toStringDemo {
    public static void main(String[] args) {
        Person human = new Person("Jack",28,true);

        System.out.println(human.showPersonInfo());
    }
}

使用toString（）方法练习

3 个答案: