Class HashMap<K,V> java.lang.Object java.util.AbstractMap<K,V> java.util.HashMap<K,V> Type Parameters: K - the type of keys maintained by this map V - the type of mapped values All Implemented Interfaces: Serializable, Cloneable, Map<K,V> Direct Known Subclasses: LinkedHashMap, PrinterStateReasons public class HashMap<K,V> extends AbstractMap<K,V> implements Map<K,V>, Cloneable, Serializable Hash table based implementation of the Map interface. This implementation provides … Continue reading HashMap in Java
Computing
Comparator Interface and sorting in Java
Comparator interface is used to order the objects of user-defined classes. A comparator object is capable of comparing two objects of two different classes. Following function compare obj1 with obj2 Syntax: public int compare(Object obj1, Object obj2): Suppose we have an array/arraylist of our own class type, containing fields like rollno, name, address, DOB etc … Continue reading Comparator Interface and sorting in Java
How Ruby block works
Blocks are one of the most powerful and often overlooked feature of ruby. I must confess that it took me a while to figure out how ruby blocks work and how they can be useful in practice. There is something about yield that makes blocks very hard to understand at first. I’m going to talk … Continue reading How Ruby block works
What does if __name__ == “__main__”: do?
A module's __name__ Every module has a name and statements in a module can find out the name of its module. This is especially handy in one particular situation - As mentioned previously, when a module is imported for the first time, the main block in that module is run. What if we want to … Continue reading What does if __name__ == “__main__”: do?
Samsung announces Connect Tag tracker that uses cellular IoT tech to help you find people and things
There is no shortage of little portable tracker devices that you can attach to your keys or your dog to ensure you never lose the things that matter most. But Samsung has today announced the Samsung Connect Tag, one of the first mobile consumer products that uses the fledgling narrowband IoT (NB-IoT) standard to connect … Continue reading Samsung announces Connect Tag tracker that uses cellular IoT tech to help you find people and things
Cellular NarrowBand IOT
NarrowBand IoT (NB-IoT) is a Low Power Wide Area Network (LPWAN) radio technology standard developed to enable a wide range of devices and services to be connected using cellular telecommunications bands. NB-IoT is a narrowband radio technology designed for the Internet of Things (IoT) and is one of a range of Mobile IoT (MIoT) technologies … Continue reading Cellular NarrowBand IOT
Enabling Simultaneous AP and Managed Mode WiFi on Raspberry Pi Zero W
Personal note: Running both an access point and a client configuration on the same network adapter (i.e., simultaneous Client/AP mode) requires support for so-called virtual interfaces. Whether a certain Wifi hardware and driver combo supports virtual interfaces and in which configurations can be found out by looking at iw list output (look for AP and … Continue reading Enabling Simultaneous AP and Managed Mode WiFi on Raspberry Pi Zero W
A good Express JS crash course
https://www.youtube.com/watch?v=gnsO8-xJ8rs Express.js, or simply Express, is a web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs. It is in fact the standard server framework for Node.js. The original author, TJ Holowaychuk, described it as a Sinatra-inspired server, meaning that … Continue reading A good Express JS crash course
What information iwconfig provides on Ubuntu
Question: lo no wireless extensions. eth0 no wireless extensions. wmaster0 no wireless extensions. wlan0 IEEE 802.11bgn ESSID:"Network" Mode:Managed Frequency:2.412 GHz Access Point: Not-Associated Tx-Power=20 dBm Retry min limit:7 RTS thr:off Fragment thr=2352 B Power Management:off Link Quality:0 Signal level:0 Noise level:0 Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 … Continue reading What information iwconfig provides on Ubuntu
Ruby on Rails in Machine Learning – Yay or Nay?
Machine Learning is a trending field of Computer Science turning computer’s computations into a new level and giving a number of unique opportunities. It’s getting more and more popular, and it’s common for modern web application as well as services, such as Netflix, Spotify, Amazon.com and Facebook. Machine Learning is a good solution for apps … Continue reading Ruby on Rails in Machine Learning – Yay or Nay?
Eric's playground 