java学习（2）

字数统计: 196阅读时长: 1 min

 2023/12/19 

java学习（2）

外置类


public class StudentTest {
    public static void main(String[] args) 
    {
    Student s=new Student("straw",20);
    System.out.println(s.getAge());
    System.out.println(s.getName());

    }
}
class Student{
    private String name;
    private int age;
    public Student()
    {
        System.out.println(name);
        System.out.println(age);
    }
    public Student(String name,int age)
    {
        this.name=name;
        this.age=age;
    }
    public void setName(String name)
    {
        this.name=name;
    }
    public int getAge()
    {
        return age;
    }
    public String getName()
    {
        return name;
    }
}

输出

1
2

20
straw

字符串拼接


public class Demo { 
    public static void main(String[] args) 
    {
        int[] arr={1,2,3};
        String str=arrToString(arr);
        System.out.println(str);
    }   
    public static String arrToString(int[] arr)
    {
        if(arr==null)
        {
            return "";
        }
        if(arr.length==0)
        {
            return "[]";
        }
        String result= "[";
        for (int i = 0; i < arr.length-1; i++) 
        {
            result+=arr[i]+",";
        }
        result=result+arr[arr.length-1]+"]";
        return result;
    }
}