Tutorial #2
Few important properties of java that needs to be learn &
understand by all java programmers whether he/she is beginner or
professional.so here it goes:-
understand by all java programmers whether he/she is beginner or
professional.so here it goes:-
*java is the first programming language that is independent of hardware for its running & work on any configuration or OS(operating system)
This is mainly because java does-not run on host computer directly,it runs on java virtual machine by converting the program into byte code that are machine independent & that virtual machine converts the byte code according to the configuration requirement type.
*Java does-not use pointers, preprocessor header files,go-to statement & many others .It also eliminate operator overloading that sometime may create chaos in programming.
*Java programs also support functions written in another common languages like C & C++. These functions are called by some special names called as native method.
*java also doesn't include C unique statement keyword sizeof, typedef & also data type like struct & unions .Neither do it has include pre-processor directives like #define,#include,#ifdef.
Instead of this it import statement ,but that use to work much differently than # include as it is attached dynamically at run -time.
*Java also don't have template class as it is present in C++;
Overview of Java
Java in its broad sense has three parts:-
1.J2SE {Core java + Advance java }
(that is mainly same as any other primitive language in its rudimentary form like C & C++
that works as a standalone feature that works on individual computer)
2.J2EE
(this is mainly for application development that helps in developing website & adding amazing
functionality in it )
3.J2ME
(this mainly helps in developing apps & games of mobile phone & has a great rising market now a
days when android apps are becoming so popular)
But for learning any particular branch of java core java of J2SE is very helpful & must in some sense so we start with learning J2SE.
Note that :- *java is pure object oriented language unlike C or C++ (which supports both) . So everything we wrote in java must be inside the class.
*Also unlike C++ class definition in java doesn't ends with semi-colon(;)
* A java application may have any number of classes but only one of them should have main method & program starts from execution of that calls & will end with the execution of that class & if that class links other classes in its body then they intern will also gets executed.
* there are three ways of commenting in java
1. // this will allow commenting for only one line;
2. /* comment */ this will allow commenting for more than one line
3./*comment
*comment continue
*comment continue
*/
Lets end this lecture with developing our first programm:-
//This program simply calculate the square-root of first ten natural numbers :-
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import java.lang.math;
class SquareRoot
{
public static void main(String args[])
{
double m;
double y;
for(int i=0;i<=10;i++)
{
y=Math.sqrt(i);
System.out.println("The square root of"+i+" = "+y);
}
}
}
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The best software for programming java is MyEclipse that can be downloaded from the given below site:-
*for 32 bit computer-http://www.filehippo.com/download_eclipse_classic_32/
*for 64 bit computer-http://www.filehippo.com/download_eclipse_classic_64/
And tutorial for writing program in MYEclipse can be sen from the given below sites:-
(remaining we will discus in the next tutorial)
