Java/C2/do-while/English

Title of script: do-while Loop

Author: TalentSprint

Keywords: loop, conditions, do-while loop, video tutorial

Visual Cue	Description
Slide 1 Welcome	Welcome to the spoken tutorial on do-while Loop in java.
Slide 2 Learning Outcomes	In this tutorial, you will learn about the do-while loop and how to use it
Slide 3 Tools Used	For this tutorial we are using Ubuntu 11.10, JDK 1.6 and Eclipse 3.7
Slide 4 Prerequisites	To follow this tutorial, you musthave knowledge on while loop in java. If not, for relevant tutorials please visit our website as shown. http://spoken-tutorial.org
Slide 5 Point on slide do-while loop	Here is the structure for do-while loop. Notice that it is similar to a while loop. It has two parts. First is the loop running condition. And the second is the loop variable
	The only difference is that the condition is written after the do block. And so the condition is checked after the execution of the statements inside the do block Now let us see an example.
Point to the code Minimize Slides and open Eclipse Eclipse should contain the following code public class DoWhileDemo{ public static void main(String[] args){ } }	Switch to eclipse, Here We have Eclipse IDE and the skeleton required for the rest of the code. We have created a class DoWhileDemo and added the main method to it.
In the main method and type, int n = 1; do { System.out.println(n); n = n + 1; } while(n <= 10);	We are going to print the numbers from 1 to 10 using a do-while loop. Type int n equalto 1 semicolon n is going to be loop variable.
	then type do open curly braces and close System.out.println(n); We shall print the value of n and then increment it. n equalto n plus 1;
	And we do this as long as n is less than or equal to 10 Outside the braces Type while in paranthesis(n less than equalto 10)
	Then close the do-while using a semi-colon
Save and Run. Point to output.	Let us see the code in action. Save and Run.
	We see that, the numbers from 1 to 10 are printed.
	now Let us understand how the code is executed.
Navigate through the code Highlight print statement. Highlight condition statement	First, the value 1 is printed and then n becomes 2. And then, the condition is checked. since it is true, again 2 is printed and n becomes 3. And so on till all the 10 numbers are printed and the value of n becomes 11. When n = 11, the condition fails and the loop stops.
	Now Let us print numbers from 50 to 40 in decreasing order.
Change n = 1 to n = 50	So we start with 50. Change n = 1 to n = 50.
Change n = n + 1 to n = n - 1	Since we are looping from a bigger number to a smaller number, we decrement the loop variable. Change n = n + 1 to n = n - 1
Change the n <= 10 to n >= 40	We loop as long as n is greater than or equal to 40. So Change the condition to n >= 40
Save and Run.	Let us look at the output. Save and Run. As we can see, the numbers from 50 to 40 are printed.
	Now let us try a different logic using the do-while loop.
	Given a number, we shall find out if it is a perfect square or not.
Inside the main method, type int n = 25;	First Clear the main method. Again Type int n = 25;
	We shall see if the value in n is a perfect square or not.
int x = 0;	Then typeint x = 0; We shall use x to store the square root of the number if it is a perfect square.
do { x = x + 1; }	Then Type do Open close braces. Inside the bracesx equal to x plus 1
do { x = x + 1; } while(x * x < n);	And outside the braces while in paranthesis (x into (star) x < n) And Close the do-while with a semi-colon
Point to the condition then increment statement.	As long a x into x is less than n, we keep incrementing the value of x.
	So when the loop stops, the reverse of this condition will be true.
	Which means either x into x must be equal to n. Or x must be greater than n.
	If x into x is equal to n, the number is a perfect square. It is not equal to n, the number is not a perfect square.
	So finally, we print the condition.
Type System.out.println(x * x == n);	System.out.println(x * x == n);
	Let us see the code in action.
Save and Run. Point to output	Save and Run. As we can see, the output is true Let us try with other perfect square.
Change n = 25 to n = 49	Change n = 25 to n = 49
	Save and Run We again get a true.
	Let us try with a number which is not a perfect square.
Change 49 to 23 Save and Run. Point to output.	Change 49 to 23. We get a false. Now let us see what happens when the value of n is 0.
Change n = 23 to n = 0	Change n = 23 to n = 0 Since 0 is not a natural number, we must get a false. Let us run the code. Save and Run.
	We see that we get false as expected.
	This happens because even before the condition x into x is less than n is checked, the value of x is incremented and it becomes 1 The loop condition fails and loop does not run.
	This way, by using a do-while loop, we make sure that 0 is not considered as a perfect square.
	This way, a do-while loop is used for solving a range of problems. Specially, when the loop must run at least once.
Minimize the Eclipse window and switch to slides. Slide 6 Summary	This brings us to the end of the tutorial. In this tutorial, we learnt about the do-while loop and how to use it
Slide 7Assignment	As an assignment for this tutorial, solve the following problem. Given a binary number, find out its decimal equivalent. Example: 11010 => 26
Slide 8About the Spoken Tutorial Project Watch the video available at[1]http://spoken-tutorial.org/What_is_a_Spoken_Tutorial It summarizes the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it	To know more about the Spoken Tutorial project, watch the video available at the following link. It summarizes the project.If you do not have good bandwidth, you can download and watch it.
Slide 9Spoken Tutorial WorkshopsThe 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@spoken-tutorial.org	The Spoken Tutorial Project Team. Conducts workshops using spoken tutorials and gives certificates for those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org.
Slide 10Acknowledgement 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	Spoken Tutorial Project is a part of the Talk to a Teacher project and is supported by the National Mission on Education through ICT, MHRD, Government of India. More information on this Mission is available at spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro
Slide 11About the contributor This tutorial has been contributed by TalentSprint www.talentsprint.com Thanks for joining	This tutorial has been contributed by TalentSprint. Thanks for joining.

Contributors and Content Editors

Arya Ratish, Sneha