language basics and Operators

Language Basics

I. Keywords: ---

These are the predefined words in the library.which consists of special meaning in programming.

In java we have 50 Keywords +10 reserved words  are there.

Ex: ---

if,else,case,switch,break,volatile,class,interface…etc.

II .Identifiers:------

 To Identify Specific  memory Blocks ..

Rules:

  1. Should Start With An Alphabet.

  2. No Spaces.

  3. Use----Underscore

III.Data Types: ---

DataType	Size	Range
byte	8bits	-12 8 To +127
char	16bits	-32768 to 32767
short	16bits	-32768 to 32767
int	32bit	-2147483648 to 2147483647
long	64bit	-9223372036854775808L to9223372036854775807L
float	32bit	1.4x10-34 to3.4x10+34 to
double	64bit	4.9E-324 to 1.7E+308
boolean		true Or false

IV: Variable:

 Storage Location

Syntax:

 <Datatype>  <Identifier/variablename>;

  Ex:  int a;  float F1=7.3f;

//If we don’t Mention F Then by Default It Takes as Double.

double abc=7.3;

Variables:----

C &C++	Java
1.Global(Can Access Anywhere)	1.Classlevel(Can Access Anywhere) or instance or reference variables
2.Local	2.Methodlevel variables

class FirstExample

 {

   public static void main(String [] args)

    {

      int x=10;

   System.out.println(x);

}

}

Operators:

 1. Arithmetic operator:

       +  -   /   *  %(modulus)

class ArithmaticOpDemo{

      public static void main(String[] args) {

                  int a=10,b=20,c;

                  c=a+b;

                  System.out.println ("the sum is :"+c);

                  System.out.println ("the mul is :"+(a*b));

                  System.out.println ("the div is :"+(a/b));

                  System.out.println ("the remainder is :"+(a%b));

      }

}

2. Increment/Decrement Operator:  

           ++     --

 They are classified into

       ++                                                                    --

Preincriment: ++a                                       Predecrement: --a                   

Postincrement:a++                                      Postdecremenet:a—

3.Compound Assignment Operator:

                ++        -=       /=   *=     %=

    class CompoundOpDemo {

      public static void main(String[] args) {

                  int x=30;

                  x+=4;

                  System.out.println("+=4:"+x);

                  int y=5;

                  y*=3;

                  System.out.println("*=3:"+y);

                  int d=50;

                  d/=5;

                  System.out.println("after div:"+d);

                  int f=40;

                  System.out.println("remainder:"+(f%=4));

      }  

}

4. Relational Operator:           

              >   >=    <     <=     ==     !=(not equal)

        When you are relational operators we will get a Boolean type of result  i.e “True/false”

      

         Class RelOpDemo {

          public static void main(String[] args) {

              int a=30,b=20;

             System.out.println (a+">"+b+":"+(a>b));

             System.out.println (a+">="+b+":"+(a>=b));

         }

       }

5. Logical Operator: 

        &&          ||         !

       (and)       (or)    (not)

class LogicalOpDemo {

      public static void main(String[] args) {

                  int a=3,b=2,c=1;

                  System.out.println((a>b)&&(a>c));

                  System.out.println((a<b)&&(a>c));

        System.out.println((a>b)||(a>c));

      }

      }

6.Bitwise Operator:(Deprecated)     

      

          &   |    ^(XOR)    >>     <<   

7. Conditional Operator:

                        ?:

     Syntax: 

               (Condition)? True part : False part

     class ConditinalOpDemo {

      public static void main(String[] args){

                  int p=20,q=30,r;

                  r=(p>q)?p:q;

                  System.out.println(r);

      }

      }