Technology Questions

String class objects are immutable objects and they represents strings( sequence of characters)

StringBuffer class objects are mutable objects representing strings and they are Thread safe

StringBuild class objects are also mutable objects representing strings and they are not Thread safe

The UTL_FILE database package can be used to read and write operating system files. You need to have read /write access rights in that directory before the package can be used.

Example to write file:

Fhandler is a variable of type UTL_FILE.FILE_TYPE

UTL_FILE.PUTF(fHandler, 'Im writing to a file\n');

Example to read file:

UTL_FILE.GET_LINE(fHandler, buf);

- The principle of least privilege is used to provide more security to the computer programs. 

- The principle allows the designing of the program such that any unauthorized access is not allowed and only the person who owns the program will be able to access it. 

- The services provided should be able to access only those products that need the services. 

- Web servers that are involved in responding the queries of the web users provide only accessing to the HTML files that will serve the purpose of the programs. 

- Computer programs should be made such that it provides secure features of logging into the program with proper authentication.

A struct is a special C data type that encapsulates other pieces of data into a single cohesive unit. Like an object, but built into C.

Android uses Dalvik Virtual Machine (DVM) which requires a special bytecode. We need to convert Java class files into Dalvik Executable files using an Android tool called "dx". In normal circumstances, developers will not be using this tool directly and build tools will care for the generation of DVM compatible files.

var obj = new Object(); or var obj = {};

Array is collection of same data type. Array size is fixed, It cannot be expanded.

But ArrayList is a growable collection of objects.ArrayList is a part of Collections Framework and can work with only objects.

JAR files are java's version of ZIP files. In fact, JAR uses the ZIP file format.

uses:

- to compress a number of . class files into one file

- to make a java executable JAR file.