如何在Java创建自定义类？

类是对象的集合。类不是现实世界的实体，它只是模板和原型或蓝图。类不占用内存。我们可以根据我们的选择编写一个自定义类以用于说明目的，下面的程序中显示了一个示例作为帮助类。

例子：

Java

// Java Program to Creating our Own Custom Class
 
// Importing input output classes
import java.io.*;
 
// Class 1
// Helper class
class Employee {
 
    // Member variables of this class
 
    // first attribute
    int id;
    // second attribute
    int salary;
    // third attribute
    String name;
 
    // Member function of this class
 
    // Method 1
    public void printDetails()
    {
        // Print and display commands
        System.out.println("My id is " + id);
        System.out.println("This is my name " + name);
    }
 
    // Method 2
    public int getSalary()
    {
 
        // Simply returning the salary
        return salary;
    }
}
 
// Class 2
// Main class
class Custom {
 
    // Main driver method
    public static void main(String[] args)
    {
 
        // Display message only
        System.out.println("This is the custom class");
 
        // Creating object of custom class in the main()
        // method Instantiating a new Employee object
        Employee harry = new Employee();
 
        // Again creating object of custom class and
        // instantiating a new Employee object
        Employee robin = new Employee();
 
        // Initializing values for first object created
        // above
        harry.id = 23;
        harry.salary = 100000;
        harry.name = "Ritu bhatiya";
 
        // Initializing values for second object created
        // above
        robin.id = 25;
        robin.salary = 150000;
        robin.name = "Amit thripathi";
 
        // Printing object attributes by
        // calling the method as defined in our class
        harry.printDetails();
        robin.printDetails();
 
        // Calling the method again of our class and
        // storing it in a variable
        int salary = robin.getSalary();
 
        // Print and display the above salary
        System.out.println("Salary of robin : " + salary
                           + "$");
 
        System.out.println("ID : " + harry.id);
    }
}

输出

This is the custom class
My id is 23
This is my name Ritu bhatiya
My id is 25
This is my name Amit thripathi
Salary of robin : 150000$
ID : 23