Operator - An operator is a symbol that tells the compiler to perform specific mathematical or logical manipulations.

Increment & Decrements Operator -

• We can apply this operators only for variables not for constant values.
• We can't apply this operators for the final variables.
• We can apply this operators for every primitive data types except boolean.

There are two types of increment operators

1. Pre Increment -

int x = ++y; // value is incremented first and then result is computed.

2. Post Increment - value is first used for computing the result and then incremented.

Arithmetic Operator + - * / %

NaN (Not a Number) - In integral arithmetic, there is no way to represent unrefined result, hence if the result is undefined we will get Arithmetic Exception

System.out.print(0/0) // Arithmetic Exception : 1 by 0

but in case of floating point arithmetic, there is way to represent undefined result, for this float & double classes contains NaN Constance, hence even though the result is undefined we won't get any run time exception.

System.out.print(0/0.0);

The only overloaded operator in Java is + operator, sometimes it acts as arithmetic addition operator and sometimes act String arithmetic operator or string concatenation operator.

int a = 10, b = 20, c = 30;

String s = "arjava";

System.out.print(a+b+c+d); // Output - 60arjava

System.out.print(a+b+d+c); // Output - 30arjava30

System.out.print(d+a+b+c); // Output - arjava102030

System.out.print(a+d+b+c); // Output - 10arjava2030

Note: If first value is integer then it will act as addition otherwise if first value is String it will act as concatenation.

Relational Operator > < >= <=

we can apply this operator to all primitive data types except boolean

Equality Operator == !=

we can apply this operator to all primitive data types including boolean. we can also use this operator for object reference, it return true if both r1 == r2 are pointing same object, here equality operator is always meant for reference or address comparison.

To apply equality between the object reference, there must be some relationship between arguments types either parent to child or child to parent otherwise we will

get compile time error : Incompatable type

instanceOf Operator -

using this operator we can check, whether the given object is of particular type or not, to use this, there must be some relationship between arguments types either parent to child or child to parent otherwise we will get compile time error : Incompatable type

x instanceOf P // x = reference type, P = class or interface

Bit Wise Operator -

& -> AND if both operands are true then the result is true

| -> OR if at least one operand is true then the result is true

^ -> if both operands are different then the result is true

Difference between & | and Short Circuit Operator && ||

& |

• Both operands should be evaluate always
• Relatively low performance
• Applicable for both boolean and integral type

&& ||

• Second operand evaluation is optional
• Relatively High Performance
• Applicable only for boolean

Type Cast Operator -

There are two types of primitive type casting

1. Implicit Type Casting - also known as Widening or Up casting

• Compiler is responsible to perform this type casting
• This type casting is required whenever we are assigning smaller data type value into bigger data type variable
• No loss of information in this type casting

2. Explicit Type Casting - also known as Narrowing or Down Casting

• Programmer is responsible to perform this type casting
• It is required whenever we are assigning bigger data type value into smaller data type variable
• There may be chance of loss of data

Assignment Operator -

There are three types of assignment operator

1. Simple assignment operator - int x = 11;

2. Chained assignment operator -

int a, b, c, d;

a = b = c = d = 20;

we can't perform chained assignment at the time of declaration

3. Compound assignment operator -

int a = 10;

a += 30

System.out.print(a) // Output - 40

These all are compound assignment operator += -= %= *= /= &= |= ^= >>= >>>= <<=

Conditional Operator ?:

also known as Ternary Operator

int a = 10, b = 20;

int x = (a>b) ? 40:50;

System.out.print(x) // Output - 50

new operator -

we can use this operator to create the object, there is no delete operator in java because destroy of useless object in java is responsibility of Garbage Collection

Operator Precedence -

• Unary Operator - [ ], ++x, --x, x++, x--, ~, !, new, <type>
• Arithmetic Operator *, /, %, +, -
• Shift Operator >>>, >>, <<
• Comparison Operator <, <=, >, >=, instanceOf
• Equality Operator ==, !=
• Bitwise Operator &, ^, |
• Short Circuit Operator &&, ||
• Conditional Operator ?:
• Assignment Operator =, +=, -=,