员工管理系统(三)

删除：

 public static boolean del(String id){
        for (int i = 0; i < employees.length; i++) {
            if(employees[i] != null && employees[i].getId().equals(id)){
                employees[i] = null;
                return true;
            }
        }
        return false;
    }

修改:

   public static boolean chg(String id,Employee em){
        for (int i = 0; i 

查询单个id： 

 public static Employee selectId(String id){
        for (int i = 0; i < employees.length; i++) {
            if(employees[i] != null && employees[i].getId().equals(id)){
                return employees[i];
            }
        }
        return null;
    }

 查询所有：

   public static Employee[] selectAll(){
        return employees;
    }