| Name |
Code |
Enumerate through a Vector using Java Enumeration Example
|
public class EnumerateThroughVectorExample
{
public static void main(String[] args)
{
//create a Vector object
Vector v = new Vector();
//populate the Vector
v.add("One");
v.add("Two");
v.add("Three");
v.add("Four");
//Get Enumeration of Vector's elements using elements() method
Enumeration e = v.elements();
/*
Enumeration provides two methods to enumerate through the elements.
It's hasMoreElements method returns true if there are more elements to
enumerate through otherwise it returns false. Its nextElement method returns
the next element in enumeration.
*/
System.out.println("Elements of the Vector are : ");
while(e.hasMoreElements())
System.out.println(e.nextElement());
}
}
|
Exception Handling
|
public class ExcepTest
{
public static void main(String args[])
{
try
{
int a[] = new int[2];
System.out.println("Access element three :" + a[3]);
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("Exception thrown :" + e);
}
System.out.println("Out of the block");
}
}
|
Create a Thread by Extending Thread
|
class MyThread extends Thread
{
int count;
MyThread()
{
count = 0;
}
public void run()
{
System.out.println("MyThread starting.");
try
{
do
{
Thread.sleep(500);
System.out.println("In MyThread, count is " + count);
count++;
} while (count < 5);
}
catch (InterruptedException exc)
{
System.out.println("MyThread interrupted.");
}
System.out.println("MyThread terminating.");
}
}
public class Main
{
public static void main(String args[])
{
System.out.println("Main thread starting.");
MyThread mt = new MyThread();
mt.start();
do
{
System.out.println("In main thread.");
try
{
Thread.sleep(250);
}
catch (InterruptedException exc)
{
System.out.println("Main thread interrupted.");
}
} while (mt.count != 5);
System.out.println("Main thread ending.");
}
}
|
Factorial
|
class Factorial
{
public static void main(String args[])
{
int num = Integer.parseInt(args[0]); //take argument as command line
int result = 1;
while(num>0)
{
result = result * num;
num--;
}
System.out.println("Factorial of Given no. is : "+result);
}
}
|
Fibonacci Series
|
class Fibonacci
{
public static void main(String args[])
{
int num = Integer.parseInt(args[0]);//taking no. as command line argument.
System.out.println("*****Fibonacci Series*****");
int f1, f2=0, f3=1;
for(int i=1;i<=num;i++)
{
System.out.print(" "+f3+" ");
f1 = f2;
f2 = f3;
f3 = f1 + f2;
}
}
}
|
File Reader/Writer
|
public class FileRead
{
public static void main(String args[])throws IOException
{
File file = new File("Hello1.txt");
// creates the file
file.createNewFile();
// creates a FileWriter Object
FileWriter writer = new FileWriter(file);
// Writes the content to the file
writer.write("This\n is\n an\n example\n");
writer.flush();
writer.close();
//Creates a FileReader Object
FileReader fr = new FileReader(file);
char [] a = new char[50];
fr.read(a); // reads the content to the array
for(char c : a)
System.out.print(c); //prints the characters one by one
fr.close();
}
}
|
Java Float Compare Example
|
public class JavaFloatCompareExample
{
public static void main(String[] args)
{
/*
To compare two float primitive values use
compare(float f1, float f2) method of Float class. This is a static method.
It returns 0 if both the values are equal, returns value less than 0 if
f1 is less than f2, and returns value grater than 0 if f2 is grater than f2.
*/
float f1 = 5.35f;
float f2 = 5.34f;
int i1 = Float.compare(f1,f2);
if(i1 > 0)
{
System.out.println("First is grater");
}
else if(i1 < 0)
{
System.out.println("Second is grater");
}
else
{
System.out.println("Both are equal");
}
/*
To compare a Float object with another Float object use
int compareTo(Float f) method.
It returns 0 if both the values are equal, returns value less than 0 if
this Float object is less than the argument, and returns value grater
than 0 if this Float object is grater than f2.
*/
Float fObj1 = new Float("5.35");
Float fObj2 = new Float("5.34");
int i2 = fObj1.compareTo(fObj2);
if(i2 > 0)
{
System.out.println("First is grater");
}
else if(i2 < 0)
{
System.out.println("Second is grater");
}
else
{
System.out.println("Both are equal");
}
}
}
|
Generate Harmonic Series
|
class HarmonicSeries
{
public static void main(String args[])
{
int num = Integer.parseInt(args[0]);
double result = 0.0;
while(num > 0)
{
result = result + (double) 1 / num;
num--;
}
System.out.println("Output of Harmonic Series is "+result);
}
}
|
HashMap
|
public class JavaHashMapExample
{
public static void main(String[] args)
{
//create object of HashMap
HashMap hMap = new HashMap();
/*
Add key value pair to HashMap using
Object put(Object key, Object value) method of Java HashMap class,
where key and value both are objects
put method returns Object which is either the value previously tied
to the key or null if no value mapped to the key.
*/
hMap.put("One", new Integer(1));
hMap.put("Two", new Integer(2));
/*
Please note that put method accepts Objects. Java Primitive values CAN NOT
be added directly to HashMap. It must be converted to corrosponding
wrapper class first.
*/
//retrieve value using Object get(Object key) method of Java HashMap class
Object obj = hMap.get("One");
System.out.println(obj);
/*
Please note that the return type of get method is an Object. The value must
be casted to the original class.
*/
}
}
|
Simple Java HashSet example
|
public class SimpleHashSetExample
{
public static void main(String[] args)
{
//create object of HashSet
HashSet hSet = new HashSet();
/*
Add an Object to HashSet using
boolean add(Object obj) method of Java HashSet class.
This method adds an element to HashSet if it is not already present in HashSet.
It returns true if the element was added to HashSet, false otherwise.
*/
hSet.add(new Integer("1"));
hSet.add(new Integer("2"));
hSet.add(new Integer("3"));
/*
Please note that add method accepts Objects. Java Primitive values CAN NOT
be added directly to HashSet. It must be converted to corrosponding
wrapper class first.
*/
System.out.println("HashSet contains.." + hSet);
}
}
|
Reviewed by Abdul hanan
on
04:57:00
Rating:
