Operators, Variables, Constructor

Operators:

it is nothing but a symbol

used to perform some operations on operands

Ex: a+b  

"a,b" -is operands," +" is operator (doing addition operation)

List of operators:

Arithmetic Operators (+ - * / % ++ --)

• +    Addition (x+y)
• -    Subtraction (x-y)
• *    Multiplication (x*y)
• /    Division (x/y)
• %    Modulus (x%y)
• ++    Increment (++x)
• --    Decrement (--x)

Relational Operators (<> <= >= == !=)

• == Equal to (x==y)
• != Not equal (x!=y)
• < Less than (x<y)
• > Greater than (x>y)
• <= Less than or equal to(x<=y)
• >= Greater than or equal to (x>=y)

Logical operators (&& || ! )

• && Logical and (x<5 && x<10)
• || Logical or (x<5 || x<4)
• ! Logical not ( !(x<5 && x<10) )

Assignment Operator (= += -= *= /= %=)

• = (x=5) this is same as (x=5)
• += (x+=5) this is same as (x=x+5)
• -= (x-=5) this is same as (x=x-5)
• *= (x*=5) this is same as (x=x*5)
• /= (x/=5) this is same as (x=x/5)
• %= (x%=5) this is same as (x=x%5)

Bitwise operators (& | ^ ~ << >>)

• & Bitwise AND
• | Bitwise OR
• ^ Bitwise exclusive OR
• ~ Bitwise Compliment
• >> Shift right
• << shift left

Ternary Operator:

ternary operator are run one code when the condition is true and another code when the condition is false.

int time=20;

String result=(time>18) ? "Good day.": "Good Evening."

System.out.println(result);

Output:

Good Evening

For More

Variables: 

• Instance variables: which are declared inside the class outside the method. They are used to store unique data for each instance of a class.
• Local variables: which are declared inside the method.

Constructor:

• It's a special method.
• No return types.
• Should be sane name as class name.
• it will call at the time of object creation.
• Used to initialize instance variable.
• if you don't write any constructor compiler will add one default constructor, if you write constructor compiler will not add default constructor.

Constructor Types

1. No parameter/ Default Constructor
2. Parameterized Constructor