Types of operators:

1.Arithmetic operator 2.Relational operator 3.Bitwise operator 4.Logical operator 5.Assignment operator 6.Misc Operator

Arithmetic Operators:

Arithmetic operators are used in mathematical expressions in the same way that they are used in algebra. The following table lists the arithmetic operators: Assume integer variable A holds 10 and variable B holds 20, then:
OperatorDescriptionExample
+Addition - Adds values on either side of the operatorA + B will give 30
-Subtraction - Subtracts right hand operand from left hand operandA - B will give -10
*Multiplication - Multiplies values on either side of the operatorA * B will give 200
/Division - Divides left hand operand by right hand operandB / A will give 2
%Modulus - Divides left hand operand by right hand operand and returns remainderB % A will give
++Increment - Increases the value of operand by 1B++ gives 21
--Decrement - Decreases the value of operand by 1B-- gives 19

Example program for using arithmetic operators


public class ArithmeticOperations {
	public static void main(String[] args) {
		int a = 40, b=30;
		System.out.println(a+b);//output: 70
		System.out.println(a-b);//output: 10
		System.out.println(a%b);//output: 10
		System.out.println(a/b);//output: 1
		System.out.println(a++);//output: 40
		System.out.println(a);//output: 41
		System.out.println(a--);//output: 41
		System.out.println(a);//output: 40
	}
}

Sample example program on arithmetic operators ++ and --


public class ArithmeticOperations2 {
	public static void main(String[] args) {
		int i=10;
		i++; //this is post increment, it adds 1 to i
		System.out.println(i);//now the i value is 11
		++i; //this is pre increment, it also adds 1 to i
		System.out.println(i);//now the i value is 12
		
		int j=20;
		j--; //this is post decrement, it minuses 1 to j
		System.out.println(j);//now the j value is 19
		--j; //this is pre decrement, it also minuses 1 to j
		System.out.println(j);//now the j valeu is 18
	}
}
Pre increment : Increment and use the value Post increment: Use the value and increment Pre decrement: Decrement and use the value Post decrement: Use the value and decrement

pre-increment, post-increment, pre-decrement, and post-decrement Example for ++ and -- operators in java.

/*
 * pre-increment, post-increment, pre-decrement, and post-decrement
 * Example for ++ and -- operators in java.
 */
public class IncrementDecrement {
	public static void main(String[] args) {
		int i=1;
		/*
		 * below line uses post increment, i.e use and increment
		 * First the line will use current i value, i.e 1
		 * and then increments it to 2
		 */
		System.out.println(i++); //prints 1
		System.out.println(i); //prints 2
		/*
		 * below line uses pre increment, i.e increment and use
		 * First the line will increment current i value, i.e to 3
		 * and then prints it, i.e 3
		 */
		System.out.println(++i); //prints 3
		System.out.println(i); //prints 3
		
		//same rule is applicable to -- operator also.
		int j=5;
		System.out.println(j--);//prints 5, use and decrement
		System.out.println(j);//prints 4
		System.out.println(--j);//prints 3, decrement and use
		System.out.println(j);//prints 3
	}
}

Relational Operators:

There are following relational operators supported by Java language. Assume variable A holds 10 and variable B holds 20, then:
OperatorDescriptionExample
==Checks if the values of two operands are equal or not, if yes then condition becomes true.(A == B) is not true.
!=Checks if the values of two operands are equal or not, if values are not equal then condition becomes true.(A != B) is true.
>Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true.(A > B) is not true.
<Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true.(A < B) is true.
>=Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true.(A >= B) is not true.
<=Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true.(A <= B) is true.

Example on how to use relational operators.


public class RelationalOperators {
	public static void main(String[] args) {
		int i=10, j=15;
		boolean b = true;
		if(i < j){
			System.out.println(i+" is less than "+j );
		}
		if(i <= j){
			System.out.println(i+" is less than or equal to "+j );
		}
		if(i > j){
			System.out.println(i+" is greater than "+j );
		}
		if(i >= j){
			System.out.println(i+" is greater than or equal to "+j );
		}
		if(i == j){
			System.out.println("i and j are same");
		}
		if(10 == i){
			System.out.println("i is 10");
		}
		if(i != j){
			System.out.println(i+" is not equal to "+j);
		}
		if(b){
			System.out.println("b is true");
		}
	}
}

The Bitwise Operators:

Java defines several bitwise operators, which can be applied to the integer types, long, int, short, char, and byte. Bitwise operator works on bits and performs bit-by-bit operation. Assume if a = 60; and b = 13; now in binary format they will be as follows: a = 0011 1100 b = 0000 1101 ------------------- a&b = 0000 1100 a|b = 0011 1101 a^b = 0011 0001 ~a = 1100 0011 The following table lists the bitwise operators. Assume integer variable A holds 60 and variable B holds 13 then:
OperatorDescriptionExample
&Binary AND Operator copies a bit to the result if it exists in both operands.(A & B) will give 12 which is 0000 1100
|Binary OR Operator copies a bit if it exists in either operand.(A | B) will give 61 which is 0011 1101
^Binary XOR Operator copies the bit if it is set in one operand but not both.(A ^ B) will give 49 which is 0011 0001
~Binary Ones Complement Operator is unary and has the effect of 'flipping' bits.(~A ) will give -61 which is 1100 0011 in 2's complement form due to a signedbinary number.
<<Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand.A << 2 will give 240 which is 1111 0000
>>Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand.A >> 2 will give 15 which is 1111
>>Shift right zero fill operator. The left operands value is moved right by the number of bits specified by the right operand and shifted values are filled up with zeros.A >>>2 will give 15 which is 0000 1111

Example for bitwise & operator (AND operator)

/*
 * Example for bitwise & operator (AND operator)
 */
public class BitwiseOperators {
	public static void main(String[] args) {
		int i=10;
		/*
		 * binary format for 10 - 00001010
		 * binary format for  2 - 00000010
		 * when applied & oper  -----------
		 *                        00000010 
		 * which is equal to 2
		 */
		System.out.println(i&2); //output is 2
	}
}

Example for bitwise | operator (OR operator - with pipe symbol)

/*
 * Example for bitwise | operator (OR operator - with pipe symbol)
 */
public class BitwiseOperators {
	public static void main(String[] args) {
		int i=10;
		/*
		 * binary format for 10 - 00001010
		 * binary format for  2 - 00000010
		 * when applied | oper  -----------
		 *                        00001010 
		 * which is equal to 10
		 */
		System.out.println(i|2); //output is 10
	}
}

Example for bitwise ^ operator (XOR operator)

/*
 * Example for bitwise ^ operator (XOR operator)
 */
public class BitwiseOperators {
	public static void main(String[] args) {
		int i=10;
		/*
		 * binary format for 10 - 00001010
		 * binary format for  2 - 00000010
		 * when applied ^ oper  -----------
		 *                        00001000 
		 * which is equal to 8
		 */
		System.out.println(i^2); //output is 8
	}
}

Example for bitwise << , >> operators (bitwise-left shit, bitwise-right shift operators)

/*
 * Example for bitwise << , >> operators 
 * (bitwise-left shit, bitwise-right shift operators)
 */
public class BitwiseOperators {
	public static void main(String[] args) {
		int i=10;
		/* << operator - working mechanism
		 * 
		 * binary format for 10 - 00001010
		 * when applied  <<2 oper --------
		 *                        00101000 
		 * which is equal to 40
		 * << is same as multiplying that number with 2(pow)n
		 * n is number of positions we are shifting.
		 * bits will be shifted to left side, that many positions.
		 * 
		 * i<<2 = i * 2(pow)2 = i*4 = 10*4 = 40
		 */
		System.out.println(i<<2); //output is 40

		/* >> operator - working mechanism
		 * 
		 * binary format for 10 - 00001010
		 * when applied  >>2 oper --------
		 *                        00000010 
		 * which is equal to 2
		 * << is same as dividing that number with 2(pow)n
		 * n is number of positions we are shifting.
		 * bits will be shifted to right side, that many positions.
		 * i>>2 = i/2(pow)2 = i/4 = 10/4 = 2
		 */

		System.out.println(i>>2); //output is 2
	}
}

Example for bitwise ~ operators (bitwise-negation operator)

/*
 * Example for bitwise ~ operators 
 * (bitwise-negation operator)
 */
public class BitwiseOperators {
	public static void main(String[] args) {
		byte i=10;
		/*
		 * bitwise ~ negation operator applies 2's compliment on a number.
		 * i is 10, binary equivalant is = 00001010
		 * when applied ~  it becomes    = 11110101
		 * it is equal to -11. 
		 */
		System.out.println(~i);
	}
}

Logical Operators:

The following table lists the logical operators. Assume Boolean variables A holds true and variable B holds false, then:
OperatorDescriptionExample
&&Called Logical AND operator. If both the operands are non-zero, then the condition becomes true.(A && B) is false
||Called Logical OR Operator. If any of the two operands are non-zero, then the condition becomes true.(A || B) is true.
!Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true then Logical NOT operator will make false.!(A && B) is true.

The Assignment Operators:

There are following assignment operators supported by Java language:
OperatorDescriptionExample
=Simple assignment operator, Assigns values from right side operands to left side operandC = A + B will assign value of A + B into C
+=Add AND assignment operator, It adds right operand to the left operand and assign the result to left operandC += A is equivalent to C = C + A
-=Subtract AND assignment operator, It subtracts right operand from the left operand and assign the result to left operandC -= A is equivalent to C = C - A
*=Multiply AND assignment operator, It multiplies right operand with the left operand and assign the result to left operandC *= A is equivalent to C = C * A
/=Divide AND assignment operator, It divides left operand with the right operand and assign the result to left operandC /= A is equivalent to C = C / A
%=Modulus AND assignment operator, It takes modulus using two operands and assign the result to left operandC %= A is equivalent to C = C % A
<<=Left shift AND assignment operatorC <<= 2 is same as C = C << 2
>>=Right shift AND assignment operatorC >>= 2 is same as C = C >> 2
&=Bitwise AND assignment operatorC &= 2 is same as C = C & 2
^=bitwise exclusive OR and assignment operatorC ^= 2 is same as C = C ^ 2
|=bitwise inclusive OR and assignment operatorC |= 2 is same as C = C | 2

Conditional Operator ( ? : )

Conditional operator is also known as the ternary operator. This operator consists of three operands and is used to evaluate Boolean expressions. The goal of the operator is to decide which value should be assigned to the variable. The operator is written as:
variable x = (expression) ? value if true : value if false   

Following is the example:

public class Test {
   public static void main(String args[]){
      int a , b;
      a = 10;
      b = (a == 1) ? 20: 30;
      System.out.println( "Value of b is : " +  b );

      b = (a == 10) ? 20: 30;
      System.out.println( "Value of b is : " + b );
   }
}
This would produce the following result:
  Value of b is : 30
  Value of b is : 20

instance of Operator:

This operator is used only for object reference variables. The operator checks whether the object is of a particular type(class type or interface type). instanceof operator is wriiten as:
( Object reference variable ) instance of  (class/interface type)
If the object referred by the variable on the left side of the operator passes the IS-A check for the class/interface type on the right side, then the result will be true. Following is the example:
public class Test
 {
   public static void main(String args[]){
      String name = "James";
      // following will return true since name is type of String
        boolean result = name instanceof String;  
      System.out.println( result );
   }
}
This would produce the following result:
true
This operator will still return true if the object being compared is the assignment compatible with the type on the right. Following is one more example:
class Vehicle {}
public class Car extends Vehicle {
   public static void main(String args[]){
      Vehicle a = new Car();
      boolean result =  a instanceof Car;
      System.out.println( result );
   }
}
This would produce the following result:
true

Increment and Decrement Operators:

1.Increment operator:

Increment operator is used to increment value of variable by 1.
Types of Increment operator 1.Pre Increment 2.Post Increment

Pre Increment:

int i=1; System.out.println(++i);

Post Increment:

int i=1; System.out.println(i++); System.out.println(i);

EXAMPLE:

   
public class MainClass {
	
      public static void main(String[] args)
            {
               int i=1;
               int j=1;
               j = i++ + ++i;
              System.out.println(i);
              System.out.println(j);
          }
      }

Pre Decrement:

int i=1; System.out.println(--i);

Post Decrement:

int i=1; System.out.println(i--);

Write a program to swap two numbers with out using temporary variable:

public class MainClass {
	public static void main(String[] args) {
		int x = 50;
		int y = 30;

		System.out.println("Before swap:");
		System.out.println("x value: "+x);
		System.out.println("y value: "+y);
		x = x+y;
		y = x-y;
		x = x-y;
		System.out.println("After swap:");
		System.out.println("x value: "+x);
		System.out.println("y value: "+y);
	}
}

Precedence of Java Operators:

Operator precedence determines the grouping of terms in an expression. This affects how an expression is evaluated. Certain operators have higher precedence than others; for example, the multiplication operator has higher precedence than the addition operator: For example, x = 7 + 3 * 2; here x is assigned 13, not 20 because operator * has higher precedence than +, so it first gets multiplied with 3*2 and then adds into 7. Here, operators with the highest precedence appear at the top of the table, those with the lowest appear at the bottom. Within an expression, higher precedence operators will be evaluated first.
Category Operator Associativity
Postfix () [] . (dot operator)Left to right
Unary ++ - - ! ~Right to left
Multiplicative * / % Left to right
Additive + - Left to right
Shift >> >>> << Left to right
Relational > >= < <= Left to right
Equality == != Left to right
Bitwise AND & Left to right
Bitwise XOR^ Left to right
Bitwise OR|Left to right
Logical AND&& Left to right
Logical OR||Left to right
Conditional?:Right to right
Assignment = += -= *= /= %= >>= <<= &= ^= |= Right to right
Comma ,Left to right