Interview Questions

unlink()-deletes the given file from the file system.
unset() -makes a variable undefined.

APK stands for Android Application Package.

Android Package (APK) is the package file format used by the Android operating system for distribution and installation of mobile apps and middleware.

The number of distinct values for a column is called index cardinality. DB2's RUNSTATS utility analyzes column value redundancy to determine whether to use a tablespace or index scan to search for data.

Basically there are many standards of Wi-Fi in the industry but some popular of them are 802.11a, 802.11b, 802.11g/n. With the support of these Wi-Fi protocols we can communicate/interact among the devices at the speed of 5Ghz to 2.4Ghz dual band communication.

If we have Wi-Fi nic card so firstly we have to install their drivers and after installation if we have Wi-Fi access point then we can see the signal strength in the right corner below just open that and find the access point to connect, if access point is configured with the security, type the key to connect and enjoy the service.

Wi-Fi is technically referred to as the 802.11 protocol. Over time, Wi-Fi has improved, giving rise to different variations of the protocol.

802.11a – This version operates at 54Mbps. It is considered as the favorite wireless LAN protocol for IP telephony.

Use Case: A use case is a description of the process which is performed by the end user for a particular task. Use case contains a sequence of step which is performed by the end user to complete a specific task or a step by step process that describe how the application and end user interact with each other. Use case is written by the user point of view.

Use case Testing: the use case testing uses this use case to evaluate the application. So that, the tester can examines all the functionalities of the application. Use case testing cover whole application, tester performs this testing in step by step process to complete one task

TTL is a value in data packet of Internet Protocol. It communicates to the network router whether or not the packet should be in the network for too long or discarded. Usually, data packets might not be transmitted to their intended destination within a stipulated period of time. The TTL value is set by a system default value which is an 8-bit binary digit field in the header of the packet. The purpose of TTL is, it would specify certain time limit in seconds, for transmitting the packet header. When the time is exhausted, the packet would be discarded. Each router receives the subtracts count, when the packet is discarded, and when it becomes zero, the router detects the discarded packets and sends a message, Internet Control Message Protocol message back to the originating host.

Chmod() is used for changing permissions on a file.

Syntax:

Chmod(file, mode)

Mode here specifies the permissions as follows:

The first number is always zero

The second number specifies permissions for the owner

The third number specifies permissions for the owner's user group

The fourth number specifies permissions for everybody else

Possible values (to set multiple permissions, add up the following numbers)

1 = execute permissions

2 = write permissions

4 = read permissions

Example:

// everything for owner, read for owner's group

chmod("test.txt",0740);

AWT are heavy-weight componenets. Swings are light-weight components. Hence swing works faster than AWT.