Saturday, April 1, 2017

What is the purpose of creating an object?

मैं सामान्य भाषा में बात को समझने का आदि हूं.
आप सोंचिये कि आपने अपने रहने के लिये एक मकान का नक्शा बनवा लिया. तो क्या आप उस नक्शे में दर्शाये गये शयनकक्ष में आराम कर सकते हैं, या फिर उस नक्शे में दिखाये गये रसोईघर में गैस चूल्हा रख सकते हैं? क्या वहां आप भोजन पका सकते है?
नहीं न?
क्युंकि ये तो एक नक्शा है और आपको जरूरत होगी कि इस नक्शे पर आधारित किसी भूभाग पर मकान बनवाई जाय, ताकि आप इसका उपयोग कर सकें.
नक्शे से मकान बनाने की आवश्यकता को आप object बनाने के purpose सेे relate कर सकते हैं. इस उदाहरण में नक्शे को class और बनाये जानेवाले मकान को object समझें.

Tuesday, March 28, 2017

Configure your new jiofi router

You can perform this part before SIM activation as well. [You will have Internet connectivity only after the SIM is activated] Connect your PC (recommended) or Phone to the JioFi 2 hotspot with the default password listed on box.

  1. Open browser, type or jiofi.local.html in the address bar and hit the enter key.
  2. The JioFi 2 router settings page will open, login with administrator as username and password.
  3. Jump into the WiFi section and change the SSID and security key as per your choice. The Security Key you set will be the WiFi password from now on.
  4. Press Apply and then OK to reboot the router. 
  5. Once the boot up completes you would need to re-connect using the new password.
  6. Again login to the Router settings page, and click on User Management. 
  7. Change the default user name and add a new password for router admin settings.
  8. Once done, click on Apply and OK.

Friday, March 24, 2017

Is JVM physically exist?

JVM (Java Virtual Machine) is not physical entity. It is just a Virtual machine. Here Virtual means not having physical existence.

What is Virtual machine?

Virtual machine is a simple software program which simulates the functions of a physical machine. This is not having physical existence, but which can perform all operations like physical machines. Physical machine whatever it is doing, all those things we can able to do on the virtual machine. Best example of virtual machine is computer; it is worked like physical calculator.

All virtual machines categorized in to 2 types

1. Hardware based or System based Virtual Machine

2. Software based or Application based or process based Virtual Machine

Hardware based virtual machines

Physically only one physical machine is there but several logical machines we can able to create on the single physical machine with strong isolation (worked independently) of each other. This type of virtual machines is called hardware based virtual machines.

Main advantage of hardware based virtual machine is effective utilization of hardware resources. Most of the times these types of virtual machines associated with admin role (System Admin, Server Admin etc). Programmers never associated with the hardware based virtual machines.

Examples of hardware based virtual machines are

1. KVM (Kernel Based VM) for Linux systems

2. VMware

3. Xen

4. Cloud Computing

Software based virtual machines

These virtual machines acts as run time engine to run a particular programming language applications. Examples of software based virtual machines are

1. JVM (Java Virtual Machine) acts as runtime engine to run Java applications

2. PVM (Parrot Virtual Machine) acts as runtime engine to run Perl applications

3. CLR (Common Language Runtime) acts as runtime engine to run .NET based applications


Ashok Kumar, Software Developer at Vistata IT