basic java programs (5)

7/31/2019 Basic Java Programs (5)

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For LoopFor loop executes group of Java statements as long as the boolean condition evaluates to true.For loop combines three elements which we generally use: initialization statement, boolean expression and increment or decrement statement.For loop syntax

for( <initialization> ; <condition> ; <statement> ){

<Block of statements>; }

The initialization statement is executed before the loop starts. It is generallyused to initialize the loop variable.Condition statement is evaluated before each time the block of statements are executed. Block of statements are executed only if the boolean condition evaluatesto true.Statement is executed after the loop body is done. Generally it is being used toincrement or decrement the loop variable.Following example shows use of simple for loop.

for(int i=0 ; i < 5 ; i++){

System.out.println(i is : + i);}

It is possible to initialize multiple variable in the initialization block of the for loop by separating it by comma as given in the below example.

for(int i=0, j =5 ; i < 5 ; i++)

It is also possible to have more than one increment or decrement section as wellas given below.

for(int i=0; i < 5 ; i++, j--)

However it is not possible to include declaration and initialization in the initialization block of the for loop.Also, having multiple conditions separated by comma also generates the compilererror. However, we can include multiple condition with && and || logical operato

rs.

Calculate Average value of Array elements using Java Example/*

Calculate Average value of Array elements using Java ExampleThis Java Example shows how to calculate average value of arrayelements.

*/public class CalculateArrayAverageExample {

public static void main(String[] args) {

//define an array

int[] numbers = new int[]{10,20,15,25,16,60,100};

/** Average value of array elements would be* sum of all elements/total number of elements*/

//calculate sum of all array elementsint sum = 0;



for(int i=0; i < numbers.length ; i++)sum = sum + numbers[i];

//calculate average valuedouble average = sum / numbers.length;

System.out.println("Average value of array elements is :

" + average);}

} /*Output of Calculate Average value of Array elements using Java Example w

ould beAverage value of array elements is : 30*/

Declare multiple variables in for loop Example/*Declare multiple variables in for loop ExampleThis Java Example shows how to declare multiple variables in Java For

loop usingdeclaration block.

*/

public class DeclaringMultipleVariablesInForLoopExample { public static void main(String[] args) {

/** Multiple variables can be declared in declaration block of for lo

op.*/

for(int i=0, j=1, k=2 ; i<5 ; i++)

System.out.println("I : " + i + ",j : "+ j + ", k : " + k);

/*

* Please note that the variables which are declared, should be ofsame type* as in this example int.*/

//THIS WILL NOT COMPILE//for(int i=0, float j; i < 5; i++);

}}

Fibonacci Series Java Example/*

Fibonacci Series Java ExampleThis Fibonacci Series Java Example shows how to create and print

Fibonacci Series using Java.*/ public class JavaFibonacciSeriesExample {


//number of elements to generate in a seriesint limit = 20;



long[] series = new long[limit];

//create first 2 series elementsseries[0] = 0;series[1] = 1;

//create the Fibonacci series and store it in an arrayfor(int i=2; i < limit; i++){

series[i] = series[i-1] + series[i-2];}

//print the Fibonacci series numbers

System.out.println("Fibonacci Series upto " + limit);for(int i=0; i< limit; i++){

System.out.print(series[i] + " ");}

}} /*Output of the Fibonacci Series Java Example would beFibonacci Series upto 200 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181

*/Generate Pyramid For a Given Number ExampleSubmitted By: mhack_rances(viado)

/*Generate Pyramid For a Given Number ExampleThis Java example shows how to generate a pyramid of numbers for

givennumber using for loop example.

*/ import java.io.BufferedReader;import java.io.InputStreamReader;

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

BufferedReader keyboard = new BufferedReader (new InputS

treamReader (System.in));

System.out.println("Enter Number:");int as= Integer.parseInt (keyboard.readLine());System.out.println("Enter X:");int x= Integer.parseInt (keyboard.readLine());

int y = 0;

for(int i=0; i<= as ;i++){

for(int j=1; j <= i ; j++){

System.out.print(y + "\t");y = y + x;

}

System.out.println("");}



}} /*Output of this example would be Enter Number:5Enter X:1 01 23 4 56 7 8 910 11 12 13 14 ---------------------------------------------- Enter Number:5Enter X:2

02 46 8 1012 14 16 1820 22 24 26 28 ---------------------------------------------- Enter Number:5Enter X:3

03 69 12 1518 21 24 2730 33 36 39 42*/

java Palindrome Number Example/*

Java Palindrome Number ExampleThis Java Palindrome Number Example shows how to find if the giv

ennumber is palindrome number or not.

*/

public class JavaPalindromeNumberExample {


//array of numbers to be checkedint numbers[] = new int[]{121,13,34,11,22,54};

//iterate through the numbers



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

int number = numbers[i];int reversedNumber = 0;int temp=0;

/** If the number is equal to it's reversed numbe

r, then* the given number is a palindrome number.** For example, 121 is a palindrome number while

12 is not.*/

//reverse the numberwhile(number > 0){

temp = number % 10;number = number / 10;reversedNumber = reversedNumber * 10 + t

emp;}

if(numbers[i] == reversedNumber)

System.out.println(numbers[i] + " is a palindrome number");else

System.out.println(numbers[i] + " is nota palindrome number");

}

}} /*Output of Java Palindrome Number Example would be121 is a palindrome number

13 is not a palindrome number34 is not a palindrome number11 is a palindrome number22 is a palindrome number54 is not a palindrome number*/

List Even Numbers Java Example/*

List Even Numbers Java ExampleThis List Even Numbers Java Example shows how to find and list e

vennumbers between 1 and any given number.

*/

public class ListEvenNumbers {


//define limitint limit = 50;

System.out.println("Printing Even numbers between 1 and

" + limit);



for(int i=1; i <= limit; i++){

// if the number is divisible by 2 then it is ev

enif( i % 2 == 0){

System.out.print(i + " ");}

}}

} /*Output of List Even Numbers Java Example would bePrinting Even numbers between 1 and 502 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50*/

List Odd Numbers Java Example/*

List Odd Numbers Java ExampleThis List Odd Numbers Java Example shows how to find and list od

d

numbers between 1 and any given number.*/ public class ListOddNumbers {


//define the limitint limit = 50;

System.out.println("Printing Odd numbers between 1 and "

+ limit);

for(int i=1; i <= limit; i++){ //if the number is not divisible by 2 then it is

oddif( i % 2 != 0){

System.out.print(i + " ");}

}}

} /*Output of List Odd Numbers Java Example would be

Printing Odd numbers between 1 and 501 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49*/

Prime Numbers Java Example/*

Prime Numbers Java ExampleThis Prime Numbers Java example shows how to generate prime numb

ersbetween 1 and given number using for loop.

*/



public class GeneratePrimeNumbersExample {


//define limitint limit = 100;

System.out.println("Prime numbers between 1 and " + limi

t);

//loop through the numbers one by onefor(int i=1; i < 100; i++){

boolean isPrime = true;

//check to see if the number is primefor(int j=2; j < i ; j++){

if(i % j == 0){

isPrime = false;break;

}}

// print the numberif(isPrime)System.out.print(i + " ");

}}

} /*Output of Prime Numbers example would bePrime numbers between 1 and 1001 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97*/

Java Pyramid 1 Example

/* Java Pyramid 1 ExampleThis Java Pyramid example shows how to generate pyramid or trian

gle likegiven below using for loop.

***************

*/

public class JavaPyramid1 {


for(int i=1; i<= 5 ;i++){

for(int j=0; j < i; j++){System.out.print("*");

}



//generate a new lineSystem.out.println("");

}}

} /*Output of the above program would be****************/

Java Pyramid 2 Example/*

Java Pyramid 2 ExampleThis Java Pyramid example shows how to generate pyramid or trian


************

****/ public class JavaPyramid2 {


for(int i=5; i>0 ;i--){


}


}}

} /* Output of the example would be************

*** */






******************************

*/public class JavaPyramid3 {


for(int i=1; i<= 5 ;i++){


}


} //create second half of pyramidfor(int i=5; i>0 ;i--){

for(int j=0; j < i; j++){

System.out.print("*");}


}

}} /* Output of the example would be************************

****** */



gle like



given below using for loop.

112123123412345

*/public class JavaPyramid4 {


for(int i=1; i<= 5 ;i++){

for(int j=0; j < i; j++){System.out.print(j+1);

}

System.out.println("");}

}

}

/* Output of the example would be112123123412345 */


Java Pyramid 6 ExampleThis Java Pyramid example shows how to generate pyramid or triangle like

given below using for loop.

*********************

*********

*/ public class JavaPyramid6 {


//generate upper half of the pyramid



for(int i=5; i>0 ;i--){


}

//create a new lineSystem.out.println("");

}

//generate bottom half of the pyramidfor(int i=1; i<= 5 ;i++){

for(int j=0; j < i; j++){

System.out.print("*");}

//create a new lineSystem.out.println("");

}

}}

/* Output of the example would be******************************

*/Read Number from Console and Check if it is a Palindrome Number

/*Read Number from Console and Check if it is a Palindrome NumberThis Java example shows how to input the number from console andcheck if the number is a palindrome number or not.

*/ import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;

public class InputPalindromeNumberExample {


System.out.println("Enter the number to check..");int number = 0;

try{

//take input from console



BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

//parse the line into intnumber = Integer.parseInt(br.readLine());

}catch(NumberFormatException ne){

System.out.println("Invalid input: " + ne);System.exit(0);

}catch(IOException ioe){

System.out.println("I/O Error: " + ioe);System.exit(0);

}

System.out.println("Number is " + number);int n = number;int reversedNumber = 0;int temp=0;

//reverse the numberwhile(n > 0){

temp = n % 10;n = n / 10;reversedNumber = reversedNumber * 10 + temp;

}

/** if the number and it's reversed number are same, the

number is a* palindrome number*/

if(number == reversedNumber)System.out.println(number + " is a palindrome nu

mber");

else System.out.println(number + " is not a palindrome number");

} } /*Output of the program would beEnter the number to check..121Number is 121121 is a palindrome number

*/

Simple For loop Example/*Simple For loop ExampleThis Java Example shows how to use for loop to iterate in Java program

.*/ public class SimpleForLoopExample {




/* Syntax of for loop is** for(<initialization> ; <condition> ; <expression> )* <loop body>** where initialization usually declares a loop variable, condition

is a* boolean expression such that if the condition is true, loop body

will be* executed and after each iteration of loop body, expression is exe

cuted which* usually increase or decrease loop variable.** Initialization is executed only once.*/

for(int index = 0; index < 5 ; index++)

System.out.println("Index is : " + index);

/** Loop body may contains more than one statement. In that case the

y should * be in the block.*/

for(int index=0; index < 5 ; index++){System.out.println("Index is : " + index);index++;}

/** Please note that in above loop, index is a local variable whose

scope

* is limited to the loop. It can not be referenced from outside the loop.*/

}} /*Output would beIndex is : 0Index is : 1Index is : 2Index is : 3Index is : 4

Index is : 0Index is : 2Index is : 4*/

sortingJava Bubble Sort Descending Order Example

/*Java Bubble Sort Descending Order ExampleThis Java bubble sort example shows how to sort an array of int

in descending



order using bubble sort algorithm.*/ public class BubbleSortDescendingOrder {


//create an int array we want to sort using bubble sortalgorithm

int intArray[] = new int[]{5,90,35,45,150,3};

//print array before sorting using bubble sort algorithmSystem.out.println("Array Before Bubble Sort");for(int i=0; i < intArray.length; i++){

System.out.print(intArray[i] + " ");}

//sort an array in descending order using bubble sort al

gorithmbubbleSort(intArray);

System.out.println("");

//print array after sorting using bubble sort algorithm

System.out.println("Array After Bubble Sort");for(int i=0; i < intArray.length; i++){System.out.print(intArray[i] + " ");

}

}

private static void bubbleSort(int[] intArray) {

/** In bubble sort, we basically traverse the array from

first* to array_length - 1 position and compare the element

with the next one. * Element is swapped with the next element if the nextelement is smaller.

** Bubble sort steps are as follows.** Compare array[0] & array[1]* If array[0] < array [1] swap it.* Compare array[1] & array[2]* If array[1] < array[2] swap it.* ...* Compare array[n-1] & array[n]* if [n-1] < array[n] then swap it.

** After this step we will have smallest element at the

last index.** Repeat the same steps for array[1] to array[n-1]**/

int n = intArray.length;int temp = 0;



for(int i=0; i < n; i++){

for(int j=1; j < (n-i); j++){

if(intArray[j-1] < intArray[j]){//swap the elements!temp = intArray[j-1];intArray[j-1] = intArray[j];intArray[j] = temp;

}

}}

}

} /*Output of the Bubble Sort Descending Order Example would be Array Before Bubble Sort5 90 35 45 150 3Array After Bubble Sort150 90 45 35 5 3

*/Java Bubble Sort Example

/*Java Bubble Sort ExampleThis Java bubble sort example shows how to sort an array of int

using bubblesort algorithm. Bubble sort is the simplest sorting algorithm.

*/ public class BubbleSort {


//create an int array we want to sort using bubble sortalgorithm

int intArray[] = new int[]{5,90,35,45,150,3};

//print array before sorting using bubble sort algorithmSystem.out.println("Array Before Bubble Sort");for(int i=0; i < intArray.length; i++){


//sort an array using bubble sort algorithmbubbleSort(intArray);

System.out.println("");

//print array after sorting using bubble sort algorithmSystem.out.println("Array After Bubble Sort");for(int i=0; i < intArray.length; i++){


}



private static void bubbleSort(int[] intArray) {

/** In bubble sort, we basically traverse the array from

first* to array_length - 1 position and compare the element

with the next one.* Element is swapped with the next element if the next

element is greater.** Bubble sort steps are as follows.** Compare array[0] & array[1]* If array[0] > array [1] swap it.* Compare array[1] & array[2]* If array[1] > array[2] swap it.* ...* Compare array[n-1] & array[n]* if [n-1] > array[n] then swap it.** After this step we will have largest element at the l

ast index.*

* Repeat the same steps for array[1] to array[n-1]**/

int n = intArray.length;int temp = 0;

for(int i=0; i < n; i++){

for(int j=1; j < (n-i); j++){

if(intArray[j-1] > intArray[j]){//swap the elements!temp = intArray[j-1];

intArray[j-1] = intArray[j];intArray[j] = temp;}

}

}

}} /*Output of the Bubble Sort Example would be

Array Before Bubble Sort5 90 35 45 150 3Array After Bubble Sort3 5 35 45 90 150 */

Break StatementBreak statement is one of the several control statements Java provide to controlthe flow of the program. As the name says, Break Statement is generally used tobreak the loop of switch statement.



Please note that Java does not provide Go To statement like other programming languages e.g. C, C++.Break statement has two forms labeled and unlabeled.Unlabeled Break statementThis form of break statement is used to jump out of the loop when specific condition occurs. This form of break statement is also used in switch statement.For example,

for(int var =0; var < 5 ; var++){

System.out.println(Var is : + var);

if(var == 3)break;

}In above break statement example, control will jump out of loop when var becomes Labeled Break StatementThe unlabeled version of the break statement is used when we want to jump out ofa single loop or single case in switch statement. Labeled version of the breakstatement is used when we want to jump out of nested or multiple loops.For example,

Outer:for(int var1=0; var1 < 5 ; var1++){

for(int var2 = 1; var2 < 5; var2++){System.out.println(var1: + var1 + , var2: + var2);

if(var1 == 3)

break Outer;

}}

Java break statement example/*Java break statement example.This example shows how to use java break statement to terminate the lo

op. */public class JavaBreakExample { public static void main(String[] args) {

/** break statement is used to terminate the loop in java. The follow

ing example* breaks the loop if the array element is equal to true.** After break statement is executed, the control goes to the statem

ent* immediately after the loop containing break statement.

*/

int intArray[] = new int[]{1,2,3,4,5};

System.out.println("Elements less than 3 are : ");for(int i=0; i < intArray.length ; i ++){if(intArray[i] == 3)

break;else



System.out.println(intArray[i]);}

}

} /*Output would beElements less than 3 are :12*/

Java break statement with label example/*Java break statement with label example.This example shows how to use java break statement to terminate the la

beled loop.The following example uses break to terminate the labeled loop while s

earching twodimensional int array.

*/ public class JavaBreakWithLableExample {


int[][] intArray = new int[][]{{1,2,3,4,5},{10,20,30,40,50}};boolean blnFound = false;

System.out.println("Searching 30 in two dimensional int array..");

Outer:for(int intOuter=0; intOuter < intArray.length ; intOuter++){Inner:for(int intInner=0; intInner < intArray[intOuter].length; intInner

++) {if(intArray[intOuter][intInner] == 30){blnFound = true;break Outer;

}

}}

if(blnFound == true)System.out.println("30 found in the array");

elseSystem.out.println("30 not found in the array");

}} /*Output would beSearching 30 in two dimensional int array..30 found in the array*/



Do While loop Example/*Do While loop ExampleThis Java Example shows how to use do while loop to iterate in Java pr

ogram.*/ public class DoWhileExample { public static void main(String[] args) {

/** Do while loop executes statment until certain condition become fa

lse.* Syntax of do while loop is** do* <loop body>* while(<condition>);** where <condition> is a boolean expression.** Please not that the condition is evaluated after executing the lo

op body.

* So loop will be executed at least once even if the condition is false.*/

int i =0;

do{System.out.println("i is : " + i);i++;

}while(i < 5);

}} /*Output would bei is : 0i is : 1i is : 2i is : 3i is : 4*/

Determine If Year Is Leap Year Java Example/*

Determine If Year Is Leap Year Java ExampleThis Determine If Year Is Leap Year Java Example shows how todetermine whether the given year is leap year or not.

*/ public class DetermineLeapYearExample {


//year we want to check



int year = 2004;

//if year is divisible by 4, it is a leap year

if((year % 400 == 0) || ((year % 4 == 0) && (year % 100!= 0)))

System.out.println("Year " + year + " is a leapyear");

elseSystem.out.println("Year " + year + " is not a l

eap year");}

} /*Output of the example would beYear 2004 is a leap year*/

Compare Two Numbers Java Example/*

Compare Two Numbers Java ExampleThis Compare Two Numbers Java Example shows how to compare two n

umbersusing if else if statements.

*/ public class CompareTwoNumbers {


//declare two numbers to compareint num1 = 324;int num2 = 234;

if(num1 > num2){

System.out.println(num1 + " is greater than " +num2);

}else if(num1 < num2){System.out.println(num1 + " is less than " + num

2);}else{

System.out.println(num1 + " is equal to " + num2);

}}

} /*

Output of Compare Two Numbers Java Example would be324 is greater than 234*/

Continue StatementContinue statement is used when we want to skip the rest of the statement in thebody of the loop and continue with the next iteration of the loop.There are two forms of continue statement in Java.Unlabeled Continue StatementLabeled Continue StatementUnlabeled Continue Statement



for(int i=0; i < intArray.length; i++){if(intArray[i] == 3)

continue;else

System.out.println(intArray[i]);}

}} /*Output would beAll numbers except for 3 are :1245*/0

basic java programs (5)

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