java - 如何在Java中使用构造函数

Question

public class Person{

    public static void main(String[] args){
        //Class constructor
        Person(String name, String status, int Age){
            this.name = name;
            this.status = status;
            this.Age = Age;
        }
        //Object creation
        Person one = new Person("John", "Single", 18);
        Person two = new Person("Kez", "Single", 21);
        Person three = new Person("Bob", "Married", 31);

        //Print out attributes
        System.out.println("Person one Profile: %s/t%s/t%d", +one.name,    +one.status, +one.Age);
        System.out.println("Person two Profile: %s/t%s/t%d", +two.name, +two.status, +two.Age);
        System.out.println("Person three Profile: %s/t%s/t%d", +three.name, +three.status, +three.Age);
    }
}

我的代码可能有什么问题？ 编译器警告的错误并不能帮助我理解问题。

Answer 1

您的代码有 5 个问题。首先，变量应该以小写字母开头，所以我将 Age 更改为 age。其次，您的构造函数不应位于 main 方法中。第三，您需要 printf 而不是 println。您还需要去掉那些 + 符号。 + 是一个运算符，需要 2 个 String(两侧各一个)，而不仅仅是一个 String。最后，我假设您的意思是 \t 而不是 /t。我已经改变了这一点，还添加了两个换行符。

更正后的代码为

public class Person {

    private String name;
    private String status;
    private int age;

    Person(String name, String status, int age){
        this.name = name;
        this.status = status;
        this.age = age;
    }

    public static void main(String[] args) {
        //Object creation
        Person one = new Person("John", "Single", 18);
        Person two = new Person("Kez", "Single", 21);
        Person three = new Person("Bob", "Married", 31);

        //Print out attributes
        System.out.printf("Person one Profile: %s\t%s\t%d\n", one.name, one.status, one.age);
        System.out.printf("Person two Profile: %s\t%s\t%d\n", two.name, two.status, two.age);
        System.out.printf("Person three Profile: %s\t%s\t%d", three.name, three.status, three.age);
    }
}