Operators and Expressions

Types of Operators in Java

Arithmetic Operators

Arithmetic Operators are used to perform simple arithmetic operations on primitive and non-primitive data types

Operator	Description
+	Additive operator (also used for String concatenation)
-	Subtraction operator
*	Multiplication operator
/	Division operator
%	Remainder operator (Modulo/Modulus operator)

Division (/) truncates decimal points for integers

Unary Operators

The unary operators require only one operand; they perform various operations such as incrementing/decrementing a value by one, negating an expression, or inverting the value of a boolean.

Operator	Description
+	Unary plus operator indicates positive value (numbers are positive without this, however)
-	Unary minus operator; negates an expression
++	Increment operator; increments a value by 1
- -	Decrement operator; decrements a value by 1
!	Logical complement operator; inverts the value of a boolean

Assignment Operator

'=' Assignment operator is used to assign a value to any variable. It has right-to-left associativity, i.e. value given on the right-hand side of the operator is assigned to the variable on the left, and therefore right-hand side value must be declared before using it or should be a constant. The assignment operator can be combined with others to create shorthand compound statements Example :

• += , Add and assign.
• -= , Subtract and assign.
• *= , Multiply and assign.
• /= , Divide and assign.
• %= , Modulo and assign

Relational Operators

These operators specify the relation between two values or expressions.

Example :

1. greater than ( > )
2. less than ( < )
3. equal to ( == )
4. greater than or equal to ( >= )
5. less than or equal to ( <= )
6. not-equal-to ( != )

Bitwise Operators

Bitwise Operators are used to perform the manipulation of individual bits of a number and with any of the integer types. They are used when performing update and query operations of the Binary indexed trees. Examples :

• & (Bitwise AND): returns bit-by-bit AND of input values.
• | (Bitwise OR): returns bit-by-bit OR of input values.
• ^ (Bitwise XOR): returns bit-by-bit XOR of input values.
• ~ (Bitwise Complement): inverts all bits (one's complement).

Shift Operators

Shift Operators are used to shift the bits of a number left or right, thereby multiplying or dividing the number by two, respectively. They can be used when we have to multiply or divide a number by two.

• << (Left shift): Shifts bits left, filling 0s (multiplies by a power of two).
• >> (Signed right shift): Shifts bits right, filling 0s (divides by a power of two), with the leftmost bit depending on the sign.
• >>> (Unsigned right shift): Shifts bits right, filling 0s, with the leftmost bit always 0.

Logical Operator

These operators are used to combine two or more relational expressions. Logical Operators :

1. And (&&)
2. Or (||)
3. Not (!)

Dot Operator

Once memory is allocated to an object, individual data members of the object can be accessed using .(dot) operator.

New Operator

Memory of an object is allocated using new operator. new operator is used to create instance of a class.

Ternary operator

The Ternary Operator is a shorthand version of the if-else statement. It has three operands and hence the name Ternary.
Syntax :

var result = condition ? val1 : val2;

Here val1 will be returned if condition is true else val2 will be returned if condition is false.

Operator Precedence

Operators	Precedence
postfix	expr++,expr- -
unary	++expr , - -expr , +expr , -expr , ~ , !
multiplicative	* , / , %
additive	+ , -
shift	<< , >> , >>>
relational	< , > , <= , >= , instanceof
equality	== , !=
bitwise AND	&
bitwise exclusive OR	^
bitwise inclusive OR	|
logical AND	&&
logical OR	||
ternary	? :
assignment	= , += , -= , *= , /= , %= , &= , ^= , |= , <<= , >>= , >>>=

Types of Expressions in Java

Pure Expression

When all the variables and constants involved in an expression belongs to the same datatype.

Impure Expression

When the variables and constants involved in an expression are of multiple datatypes, it known as an impure expression.