Java/C2/Nested-if/English

Author : TalentSprint

Script Title : Nested-If and Ternary Operator

Keywords : If else conditional statements, Ternary operator, nested-if, video tutorial

Visual Clue	Description
Slide 1 Welcome	Welcome to the spoken tutorial on Nested-If and Ternary Operator in java.
Slide 2 Learning Objectives	By the end of this tutorial you should be able to: Explain Nested-If Statements and Ternary operators. Use them in a Java program.
Slide 3 Tools Used	For this tutorial we are using: Ubuntu 11.10, JDK 1.6,and Eclipse 3.7.0
Slide 4 Pre-requisites	To follow this tutorial, you should know, - the usage of relational and logical operators. - if...else control flow statements. If not, for relevant tutorial please visit our website which is as shown.
Slide 5 Nested-If statements	An if statement within another if statement is called a nested-if statement.
Slide 6 Syntax for Nested-If Statement Point to the line of code as you explain. if (condition1) { if (condition2) { Statement or block 1 } else { Statement or block 2 } } else { Statement or block 3 }	Let us look at the syntax for writing the Nested-If statement. In this case, if condition 1 is true, then the program checks for condition 2. Condition 2 is given using another If statement. If condition 2 is true, then the program executes Statement or block 1. Else, it executes Statement or block 2. If condition 1 is false, then the program will not check condition2. Instead will directly jump to its else statement i.e. block 3.
	Let us try and example to understand that better
Point to the code { Minimize slides and open Eclise. It should contain the following } public class NestedIfDemo { public static void main(String args[]) { } }	We have the eclipse IDE and the skeleton required for the rest of the code. We have created a class NesedIfDemo and added the main method to it.
Type int n = -5; Highlight int n = -5;	We shall check if the given number is a even number or an odd number. But we will also handle negative numbers using a nested-if. So type int n = minus 5; We have created a variable to store the number. Now we shall write the if conditions.
Type if (n < 0) { System.out.println(“Negative number”); }	Type if (n < 0) open curly bracket System.out.println(“Negative number”); close curly bracket We first see if the number is a negative number. If yes then we will not check for even and odd.
	Then if the number is not a negative, we then check for even and odd.
Type after the if statement. else{ }	Type else { } Now if the execution has come to the else part. It means that the number is non negative. So we check for odd or even inside this else part.
inside else, type if (n % 2 == 0) { System.out.println(“Even number”); } else { System.out.println(“Odd number”); }	Type if (n percent 2 equalto equalto 0) { System.out.println(“Even number”); } else { System.out.println(“Odd number”); } So we make sure that negative numbers are not considered for odd or even check.
	Now let us see the code in action.
Save and Run	As we can see, we get the output “negative”. Let us try a positive number
Change n = -5 to n = 5	Change n = -5 to n = 5 Save and Run.
Point to the output	As we can see, the output is odd as expected. Let us try an even number
Change n = 5 to n = 10	Change n = 5 to n = 10. Save and run.
Point to the output.	As we can see, the output is “even” as expected.
Highlight the code	This process of including an if statement inside another, is called nested-if. There is no limit to the amount of nesting. But it is a good practice to not go beyond 3 levels of nesting.
Remove everything inside the Main method	Now we shall look at the ternary operator. First let me clean up the Main method.
	We shall write a program that divides a number by 2. It is a very trivial program but the issue comes in dividing odd numbers. When 7 is divided by 2, we get 3. But what if we want the result to be rounded off. Which means, when 7 is divided by 2, we get must 4 and not 3 In simple terms, we need the next number.
	Let us see how to write such a program.
Type int n, nHalf;	Type int n, nHalf; We will store the number in n and the half number in nHalf
Type n = 5; if (n % 2 == 0) { nHalf = n / 2; } else { nHalf = (n + 1) / 2; }	Type n = 5; if (n % 2 == 0) { nHalf = n / 2; } else { nHalf = (n + 1) / 2; } We check if the number is even or odd and do the division accordingly.
Type System.out.println(nHalf);	Let us add a print statement to see the program in action. Type System.out.println(nHalf);
Save and Run. Point to the output.	Save and Run. As we can see, our objective is met.
Point to the code.	But if we notice, all we are doing is, setting the value of a variable depending on a condition. There is more syntax than logic in our program. This is when ternary operator makes code simpler.
{Switch to Slides} Slide 7 Ternary Operator.	A conditional operator providing results similar to nested-if. Provides a short syntax and is denoted by a question mark. Takes three operands at a time.
Slide 8 Point to the syntax Syntax of Ternary Operator Syntax: Result = Expression ? Operand 1 : Operand 2	Let us learn about the syntax of Ternary Operator. The expression is the condition that has to be checked. Operand 1 is the value of the variable Result if the condition is true. Operand 2 is the value if the condition is false. Let us use it in our program.
{Switch to eclipse} Remove the if-else statement	First let us remove the if-else statement.
Type nHalf = n % 2 == 0 ? n / 2 : (n + 1) / 2	Type nHalf = n % 2 == 0 ? n / 2 : (n + 1) / 2 This statement reads, if n is even, nHalf is n by 2. Otherwise, it is n plus 1 by 2.
Save and Run.	Let us now see it in action. Save and Run.
Point to the output.	As we can see, the output is as expected. This way, ternary operator reduces clutter in the code and improves readability.
Slide 9 Summary	We have come to the end of this tutorial. In this tutorial we have learnt: About Nested-If Statements and Ternary Operator Usage of Nested-If Statements and Ternary Operator in a Java program
Slide 10 Assignment	Now take an assignment on Nested-If and Ternary operator. Write java program for the following. Check whether a number is even and also a multiple of 11 using nested-if. Identify the largest number among the two given numbers using Ternary operator.
Slide 11 About 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 12 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 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 13 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	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 14 About 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, PoojaMoolya, Sneha