Java項目中每一個類都可以有一個main方法，但只有一個main方法會被執行，其他main方法可以對類進行單元測試。
public class StaticTest { public static void main(String[] args) { Employee[] staff=new Employee[3]; staff[0]=new Employee("Tom",40000); staff[1]=new Employee("Dick",60000); staff[2]=new Employee("Harry",65000); for(Employee e:staff) { e.setId(); System.out.println("name="+e.getName()+",id="+e.getId()+",salary="+e.getSalary()); } int n=Employee.getNextId(); System.out.println("Next available id="+n); } } class Employee { public Employee(String n,double s) { name=n; salary=s; id=0; } public String getName() { return name; } public double getSalary() { return salary; } public int getId() { return id; } public void setId() { id=nextId; nextId++; } public static int getNextId() { return nextId; } public static void main(String[] args) { Employee e=new Employee("Harry",50000); System.out.println(e.getName()+" "+e.getSalary()); } private String name; private double salary; private int id; private static int nextId=1; }
java Employee可以得到
Harry 50000.0
java StaticTest可以得到
name=Tom,id=1,salary=40000.0
name=Dick,id=2,salary=60000.0
name=Harry,id=3,salary=65000.0
Next available id=4