As we know the AUTO_INCREMENT column must have the PRIMARY KEY constraint on it also hence when we will try to drop PRIMARY KEY constraint from the AUTO_INCREMENT column the MySQL returns an error message regarding the incorrect table definition. The example below will demonstrate it −ExampleSuppose we have ‘Accounts’ ... Read More

To get the time difference between two timestamps, try to run the following code. Here, we are calculating the total number of hours, minutes and seconds between two timestamps −ExampleLive Demo           JavaScript Dates                       ... Read More

Hashtable was part of the original java.util and is a concrete implementation of a Dictionary. However, Java 2 re-engineered Hashtable so that it also implements the Map interface. Thus, Hashtable is now integrated into the collections framework. It is similar to HashMap, but is synchronized.Like HashMap, Hashtable stores key/value pairs ... Read More

Some of the prominently used networks in today’s world are −InternetIEEE 802.11 for Wireless LANRFID and Sensor NetworksInternetInternet is a global collection of vast number of dissimilar networks that are interconnected together. Internet uses the TCP/IP protocol and provides varied services. The networks forming the Internet may be private, public, ... Read More

The host-to-network layer is the lowest layer of the TCP/IP model and is concerned with the physical transmission of data. It is also called a network interface layer or link layer. It can be considered as the combination of physical layer and data link layer of the OSI model.The functions ... Read More

A Connectionless service is a data communication between two nodes where the sender sends data without ensuring whether the receiver is available to receive the data. Here, each data packet has the destination address and is routed independently irrespective of the other packets. Thus the data packets may follow different ... Read More

The physical layer (Layer 1) deals with transmission of individual bits from one node to another over a physical medium.The main functions of the physical layer are as follows −It defines the physical characteristics and functions of the physical devices and interfaces so that transmission can occur. It states the ... Read More

A home network is a small sized LAN that is used to connected devices within the small area of a home. It facilitates sharing of files, peripheral devices, programs and Internet access among the computers in a home. Home networks may be wired, i.e. connections within devices are done with ... Read More

Use the String() method in JavaScript to convert to String. You can try to run the following code to learn how to convert { } to String in JavaScript.ExampleLive Demo           Convert {} to String                var myVal = {};          document.write("String: " + String(myVal));          

Use the document.images property in JavaScript to get the number of tags in a document.ExampleYou can try to run the following code to implement document.images property in JavaScript.Live Demo           JavaScript Example               TutorialsPoint Tutorials                            var num = document.images.length;          document.write("How many images? "+num);