Sneha at 03:49, 9 May 2013

2013-05-09T03:49:47Z

Chandrika: Created page with ''''Title of script''': While Loop '''Author''': TalentSprint '''Keywords:''' loop, conditions, while loop, video tutorial {| style="border-spacing:0;" | style="border:0.035c…'

2012-11-27T10:23:46Z

Created page with ''''Title of script''': While Loop '''Author''': TalentSprint '''Keywords:''' loop, conditions, while loop, video tutorial {| style="border-spacing:0;" | style="border:0.035c…'

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'''Title of script''': While Loop

'''Author''': TalentSprint

'''Keywords:''' loop, conditions, while loop, video tutorial

{| style="border-spacing:0;"
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| '''Visual Cue '''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| '''Description'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 1

'''Welcome'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Welcome to the spoken tutorial on''' While Loop '''in java'''.'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 2

'''Learning Outcomes'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| In this tutorial, you will learn

'''About the while loop.'''

'''To use it.'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 3

'''Tools Used'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| For this tutorial we are using

'''Ubuntu 11.10''',

'''JDK 1.6''' and

'''Eclipse 3.7'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 4

'''Prerequisites'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| To follow this tutorial, you must have knowledge on '''relational operators in Java'''

If not, for relevant tutorials please visit our website which is as shown. [http://spoken-tutorial.org/ http][http://spoken-tutorial.org/ ://][http://spoken-tutorial.org/ spoken][http://spoken-tutorial.org/ -][http://spoken-tutorial.org/ tutorial][http://spoken-tutorial.org/ .][http://spoken-tutorial.org/ org]

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 5

'''While loop'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Here is the structure of a while loop.

It has two parts.

One is the '''loop running condition''' and the other is the '''loop variable.'''

Let us look at an example. Switch to Eclipse

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| '''Point to the code'''

Minimize Slides and open Eclipse

Eclipse should contain the following code.

'''public class WhileDemo{'''

'''public static void main(String<nowiki>[] </nowiki>args){'''

'''}'''

'''}'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We have the skeleton code required.

I have created a class WhileDemo and added the main method to it.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Type in main method,

'''int n = 1;'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We shall print numbers from 1 to 10 using a while loop.

Type '''''int n = 1'' '''''semi-colon.''

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Highlight

'''int n = 1;'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| We have created an integer '''n''' that we would be using inside the loop.

This is called the loop variable.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Type in next line,

'''while (n<nowiki> <= 10)</nowiki>'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Then type '''''while '''''within ''parenthesis '''n''' less than equalto'' '''''10'''''

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Highlight

'''while (n<nowiki> <= 10)</nowiki>'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| This statement is called the looping condition.

It means the loop will run as long as this condition is true.

In our case, it will run as long as the value of '''n''' is less than or equal to 10.

And it will stop only when the value of '''n''' become greater than 10.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change the '''while... '''to

while (n<nowiki> <= 10) {</nowiki>

System.out.println(n);

n = n + 1;

}
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Inside the loop, we shall print the value of '''n''' and then increment it.

Type '''System.out.println(n);'''

'''n = n + 1;'''

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Highlight print statement

Then increment statement
| style="border:0.035cm solid #000000;padding:0.176cm;"| This way, first 1 is printed and then the value of n becomes 2.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Highlight condition

Highlight print statement

Then increment statement.
| style="border:0.035cm solid #000000;padding:0.176cm;"| Then the loop condition is checked.

The condition is true.

Then 2 is printed and the value of n becomes 3.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Highlight condition

| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| This happens till 10 is printed and the value of n becomes 11.

Once the value of n is 11, the condition '''n<nowiki> <= 10</nowiki>''' is not true'''.'''

And hence the loop stops.

Let us see the code in action.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Save and run. Point to output
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Save.

Run the code.

As we can see, the numbers from 1 to 10 are printed.

Now let us print numbers from '''50''' to '''40'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change '''n = 1''' to '''n = 50'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We start with 50.

'''So Change n = 1 to n = 50'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change '''n<nowiki> <= 10</nowiki>''' to '''n >= 40'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We go till 40.

In other words as long as n ''is greater than or equal to ''40.

Change '''n''' ''lessthan equal to '''''10 '''to '''n''' ''greater than equal to '''''40'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change '''n = n + 1''' to '''n = n - 1'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| since we are looping from a bigger number to a smaller number, we have decrement the loop variable.

Change '''n + 1''' to '''n - 1'''

Let us now see the output.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Save and run. Point to output
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| As we can see, the output is as expected.

Now we shall print the first 10 multiples of 7.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change '''n = 50''' to '''n = 7'''

Change '''n >= 40''' to '''n<nowiki> <= 70</nowiki>'''

Change '''n = n – 1''' to '''n = n + 7'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| To do that, we start with 7 and end with 70.

So change '''n = 50''' to '''n = 7'''

'''n''' ''greater than equal to '''''40 to n''' ''less than equal to '''''70'''

This way, we make sure the loop stops at 70.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"|
| style="border:0.035cm solid #000000;padding:0.176cm;"| To get the multiples, we shall increment the loop variable by 7.

So, change '''n - 1''' to '''n + 7'''

Save. Run.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Save and run. Point to output
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| As we can see, the output is the first 10 multiples of 7.

We can also use a while loop to get the sum of digits of a number.

Let us see how to do so.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change '''n = 7''' to '''n = 13876'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| First clear the main method.

We start with the number.

'''n''' ''equal to'' '''13876'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Add '''int dSum = 0''' as the next line
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| '''int dSum '''''equal to'' '''0'''

This variable will contain the sum of digits.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change '''n<nowiki> <= 70</nowiki>''' to '''n > 0'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change '''n''' ''less than equal to '''''70 '''to '''n '''''greater than '''''0'''

The reason for using this condition will be evident in a while.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Remove '''n = n + 7''' and add this

'''dSum = dSum + (n % 10);'''

'''n = n / 10;'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| To get the sum of digits, we must first get the digits.

We do that by using the modulo operator.

Type '''dSum = dSum + (n % 10)'''

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"|
| style="border:0.035cm solid #000000;padding:0.176cm;"| Now after adding that digit, we remove the digit by dividing the number by 10.

Type n = n / 10

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Point to the code : '''dSum'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| So when the loop runs for the first time, '''dSum '''will be 6 and n will be 1387.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Point to the code : '''dSum '''and '''n'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| After the second run, '''dSum''' will be 13, which is the sum of last two digits

'''n''' will become 138.

So on, as the loop progresses, the digits will be added to '''dSum.'''

And the value of '''n''' will become zero.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"|
| style="border:0.035cm solid #000000;padding:0.176cm;"| Finally, we print the dSum.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Change '''println(n)''' to '''println(dSum)'''

save and run. Point to output
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Type '''System.out.println(dSum)'''

Save and run.

As we can see, the sum of digits has been printed.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"|
| style="border:0.035cm solid #000000;padding:0.176cm;"| This way, a while loop, is one of the most fundamental constructs in programming, can be used.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Minimize the '''Eclipse''' window and switch to slides.

Slide 6

'''Summary'''
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We have come to the end of this tutorial.

In this tutorial we have learnt

* The while loop
* how to use it

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 7'''Assignment'''

| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| As an assignment for this tutorial solve the following problem.

Given a number, compute its reverse by using a while loop.

Example: 19435 => 53491

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 8'''About the Spoken Tutorial Project'''

* Watch the video available at[http://spoken-tutorial.org/What_is_a_Spoken_Tutorial ][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial http][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial ://][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial spoken][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial -][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial tutorial][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial .][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial org][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial /][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial What][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial _][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial is][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial _][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial a][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial _][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial Spoken][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial _][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial Tutorial]

* It summarizes the Spoken Tutorial project

* If you do not have good bandwidth, you can download and watch it

| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| To know more about the '''Spoken Tutorial''' project, watch the video available at the following link, that summarizes the Spoken Tutorial project

If you do not have good bandwidth, you can download and watch it.

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 9'''Spoken Tutorial Workshops'''The Spoken Tutorial Project Team

* Conducts workshops using spoken tutorials

* Gives certificates for those who pass an online test

* For more details, please write to [mailto:contact@spoken-tutorial.org contact][mailto:contact@spoken-tutorial.org @][mailto:contact@spoken-tutorial.org spoken][mailto:contact@spoken-tutorial.org -][mailto:contact@spoken-tutorial.org tutorial][mailto:contact@spoken-tutorial.org .][mailto:contact@spoken-tutorial.org org]

| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| The Spoken Tutorial Project Team, Conducts workshops using spoken tutorials, Gives certificates for those who pass an online test

For more details, please write to '''contact AT spoken HYPHEN tutorial DOT org.'''

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 10'''Acknowledgement'''

* Spoken Tutorial Project is a part of the Talk to a Teacher project

* It is supported by the National Mission on Education through ICT, MHRD, Government of India

* More information on this Mission is available at

* [http://spoken-tutorial.org/NMEICT-Intro http][http://spoken-tutorial.org/NMEICT-Intro ://][http://spoken-tutorial.org/NMEICT-Intro spoken][http://spoken-tutorial.org/NMEICT-Intro -][http://spoken-tutorial.org/NMEICT-Intro tutorial][http://spoken-tutorial.org/NMEICT-Intro .][http://spoken-tutorial.org/NMEICT-Intro org][http://spoken-tutorial.org/NMEICT-Intro /][http://spoken-tutorial.org/NMEICT-Intro NMEICT][http://spoken-tutorial.org/NMEICT-Intro -][http://spoken-tutorial.org/NMEICT-Intro Intro]

| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| '''Spoken Tutorial '''Project is a part of the '''Talk to a Teacher''' project. It is supported by the '''National Mission on Education through ICT, MHRD, Government of India. '''More information on this Mission is available at the following link

|-
| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 11'''About the contributor'''

* This tutorial has been contributed by '''TalentSprint'''
* '''www.talentsprint.com'''

* Thanks for joining

| style="border:0.035cm solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| This tutorial has been contributed by '''TalentSprint'''. Thanks for joining.

|}

Java/C2/while-loop/English - Revision history

Sneha at 03:49, 9 May 2013

Chandrika: Created page with ''''Title of script''': While Loop '''Author''': TalentSprint '''Keywords:''' loop, conditions, while loop, video tutorial {| style="border-spacing:0;" | style="border:0.035c…'