Swapping example in C:

Swapping:

#include
int main() { 

int a, b, temp;

 printf("Enter the value of a and b: \n");

 scanf("%d %d", &a, &b); 

 printf("Before swapping a=%d, b=%d \n", a, b);

 /*Swapping logic */

 temp = a;

 a = b;

 b = temp; 

printf("After swapping a=%d, b=%d", a, b);

 return 0;

 }

 Output:

 Enter the values of a and b: 2 3 

Before swapping a=2, b=3 

After swapping a=3, b=2

Basic Operators

Java Basic Operators:

Java provides a rich set of operators to manipulate variables. We can divide all the Java operators into the following groups:

The Arithmetic Operators:

Operator	Description	Example
+	Addition - Adds values on either side of the operator	A + B will give 30
-	Subtraction - Subtracts right hand operand from left hand operand	A - B will give -10
*	Multiplication - Multiplies values on either side of the operator	A * B will give 200
/	Division - Divides left hand operand by right hand operand	B / A will give 2
%	Modulus - Divides left hand operand by right hand operand and returns remainder	B % A will give 0
++	Increment - Increase the value of operand by 1	B++ gives 21
--	Decrement - Decrease the value of operand by 1	B-- gives 19

The Relational Operators:

Operator	Description	Example
==	Checks if the value of two operands are equal or not, if yes then condition becomes true.	(A == B) is not true.
!=	Checks if the value 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.

The Bitwise Operators:

Operator	Description	Example
&	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 eather 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 efect of 'flipping' bits.	(~A ) will give -60 which is 1100 0011
<<	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

The Logical Operators:

Operator	Description	Example
&&	Called Logical AND operator. If both the operands are non zero then then condition becomes true.	(A && B) is false.
||	Called Logical OR Operator. If any of the two operands are non zero then then 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:

Operator	Description	Example
=	Simple assignment operator, Assigns values from right side operands to left side operand	C = A + B will assigne value of A + B into C
+=	Add AND assignment operator, It adds right operand to the left operand and assign the result to left operand	C += 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 operand	C -= 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 operand	C *= 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 operand	C /= A is equivalent to C = C / A
%=	Modulus AND assignment operator, It takes modulus using two operands and assign the result to left operand	C %= A is equivalent to C = C % A
<<=	Left shift AND assignment operator	C <<= 2 is same as C = C << 2
>>=	Right shift AND assignment operator	C >>= 2 is same as C = C >> 2
&=	Bitwise AND assignment operator	C &= 2 is same as C = C & 2
^=	bitwise exclusive OR and assignment operator	C ^= 2 is same as C = C ^ 2
|=	bitwise inclusive OR and assignment operator	C |= 2 is same as C = C | 2

Misc Operators

There are few other operators supported by Java Language.

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

instanceOf 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 ) instanceOf (class/interface type)

Sorting Array:

Sorting Array:

import java.util.Arrays;

 public class MainClass { 

   public static void main(String args[]) throws Exception {

             int array[] = { 2, 5, -2, 6, -3, 8, 0, -7, -9, 4 }; 

                Arrays.sort(array);

                   printArray("Sorted array", array); 

                     int index = Arrays.binarySearch(array, 2);

                      System.out.println("Found 2 @ " + index); 

                    }

           private static void printArray(String message, int array[]) {

               System.out.println(message + ": [length: " + array.length + "]");

                   for (int i = 0; i < array.length; i++) {

                      if(i != 0){ System.out.print(", ");

                   }

 System.out.print(array[i]); 

 } 

 System.out.println(); }

 } 

Result:

The above code sample will produce the following result.
Sorted array: [length: 10] -9, -7, -3, -2, 0, 2, 4, 5, 6, 8 Found 2 @ 5

Create New Thread Using Runnable Example

Create New Thread Using Runnable Example

public class CreateThreadRunnableExample implements Runnable{

/*
* A class must implement run method to implement Runnable
* interface. Signature of the run method is,
*
* public void run()
*
* Code written inside run method will constite a new thread.
* New thread will end when run method returns.
*/
public void run(){

for(int i=0; i < 5; i++){
System.out.println("Child Thread : " + i);

try{
Thread.sleep(50);
}
catch(InterruptedException ie){
System.out.println("Child thread interrupted! " + ie);
}
}
System.out.println("Child thread finished!");
}

public static void main(String[] args) {
                /*
* To create new thread, use
* Thread(Runnable thread, String threadName)
* constructor. */

Thread t = new Thread(new CreateThreadRunnableExample(), "My Thread");

/*
* To start a particular thread, use
* void start() method of Thread class.
* Please note that, after creation of a thread it will not start
* running until we call start method.
*/

t.start();
for(int i=0; i < 5; i++){
System.out.println("Main thread : " + i);
try{
Thread.sleep(100);
}
catch(InterruptedException ie){
System.out.println("Child thread interrupted! " + ie);
}
}
System.out.println("Main thread finished!");
}
}

Output:

Main thread : 0
Child Thread : 0
Child Thread : 1
Main thread : 1
Main thread : 2
Child Thread : 2
Child Thread : 3
Main thread : 3
Main thread : 4
Child Thread : 4
Child thread finished!
Main thread finished!

Add or substract days to current date using Java Calendar

Add or substract days to current date using Java Calendar:

import java.util.Calendar;

public class AddDaysToCurrentDate {

public static void main(String[] args) {
                                                         //create Calendar instance
Calendar now = Calendar.getInstance();
    System.out.println("Current date : " + (now.get(Calendar.MONTH) + 1)+ "-"+now.get(Calendar.DATE) + "-"+ now.get(Calendar.YEAR));
                                           //add days to current date using Calendar.add method
now.add(Calendar.DATE,1);
          System.out.println("date after one day : " + (now.get(Calendar.MONTH) + 1)+ "-"+ now.get(Calendar.DATE) + "-" + now.get(Calendar.YEAR));
                                                  //substract days from current date using Calendar.add method
now = Calendar.getInstance();
now.add(Calendar.DATE, -10);
    System.out.println("date before 10 days : " + (now.get(Calendar.MONTH) + 1)+ "-"+now.get(Calendar.DATE)+ "-"+ now.get(Calendar.YEAR));

}
}

Output:
Current date : 12-25-2007
date after one day : 12-26-2007
date before 10 days : 12-15-2007