Difference between revisions of "Java/C2/Nested-if/English-timed"
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− | |In the else part type within curly brackets '''nHalf equal to within brackets n+1 the whole divided by 2 | + | |In the '''else''' part, type: within curly brackets '''nHalf''' equal to within brackets '''n+1''' the whole divided by '''2''' semicolon |
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− | | So Type '''System.out.println within brackets nHalf semicolon''' | + | | So Type '''System.out.println''' within brackets '''nHalf''' semicolon''' |
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− | | But if we notice, all we are doing is | + | | But if we notice, all we are doing is setting the value of a variable depending on a condition. |
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| 06:27 | | 06:27 | ||
− | |There is more syntax than logic in our program. | + | |There is more syntax than '''logic''' in our program. |
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− | | | + | | '''Ternary Operator''' is a '''conditional''' operator providing results similar to '''nested-if'''. |
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− | | It | + | | It takes three '''operands''' at a time. |
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| 06:48 | | 06:48 | ||
− | | Let us learn about the syntax of Ternary Operator. | + | | Let us learn about the syntax of '''Ternary Operator'''. |
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|07:12 | |07:12 | ||
− | |First let us remove the if-else statement. | + | |First, let us remove the '''if-else''' statement. |
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− | |Type '''nHalf equal to n modulus 2 double equal to 0 question mark n / 2 colon within brackets n + 1 the whole divided by 2''' semi-colon | + | |Type '''nHalf''' equal to '''n''' modulus '''2''' double equal to '''0''' question mark '''n / 2''' colon within brackets '''n + 1''' the whole divided by '''2''' semi-colon |
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|07:41 | |07:41 | ||
− | |This statement reads | + | |This statement reads: |
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|07:43 | |07:43 | ||
− | | | + | |If 'n' is even, 'nHalf' is 'n by 2'. Otherwise it is 'n plus 1 by 2'. |
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− | |'''Save''' and '''Run'''the file. Press Ctrl S and Ctrl F11 | + | |'''Save''' and '''Run'''the file. Press '''Ctrl S''' and '''Ctrl F11''' keys. |
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− | |This way, ternary operator reduces clutter in the code and improves readability. | + | |This way, '''ternary operator''' reduces clutter in the code and improves readability. |
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− | |* About Nested-If Statements and Ternary Operator | + | |* About '''Nested-If Statements''' and '''Ternary Operator''' |
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| 08:15 | | 08:15 | ||
− | |* Usage of Nested-If Statements and Ternary Operator in a Java program | + | |* Usage of '''Nested-If Statements''' and '''Ternary Operator''' in a Java program. |
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− | |'''Nested-If''' and '''Ternary operator'''. Write java program for the following. | + | |'''Nested-If''' and '''Ternary operator'''. Write java program for the following. |
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− | | It summarizes the spoken-tutorial project.If you do not have good bandwidth, you can download and watch it. | + | | It summarizes the spoken-tutorial project. If you do not have good bandwidth, you can download and watch it. |
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− | | | + | | Spoken Tutorial Project is a part of the Talk to a Teacher project and |
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| 09:11 | | 09:11 | ||
− | | | + | |it is supported by the National mission on Education through ICT, MHRD, Government of India. |
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| 09:17 | | 09:17 |
Revision as of 12:45, 25 March 2015
Time | Narration |
00:02 | Welcome to the spoken tutorial on Nested-If and Ternary Operator in java. |
00:07 | By the end of this tutorial you should be able to:
|
00:17 | For this tutorial we are using:
Ubuntu v 11.10, JDK 1.6,and EclipseIDE 3.7.0 |
00:27 | To follow this tutorial, you should know, |
00:29 | about the usage of relational and logical operators. |
00:33 | And if...else control flow statements. |
00:36 | If not, for relevant tutorials, please visit our website which is as shown. |
00:41 | Nested if statements: An If statement within another if statement is called a nested-if statement. |
00:49 | Now let us look at the syntax for writing the Nested-If statement. |
00:53 | In this case, if condition 1 is true, then the program checks for condition 2. |
00:59 | Condition 2 is given using another If statement. |
01:03 | If condition 2 is true then the program executes Statement or block 1. |
01:09 | Else, it executes Statement or block 2.
|
01:13 | If condition 1 is false, then the program will not check condition2. |
01:18 | Instead it will directly jump to its else statement i.e. block 3. |
01:24 | Now, Let us try an example to understand that better. |
01:28 | We have the eclipse IDE and the skeleton required for the rest of the code. |
01:32 | We have created a class NesedIfDemo and added the main method to it. |
01:37 | We shall check if the given number is a even number or an odd number. |
01:42 | we will also handle negative numbers using a nested-if. |
01:46 | So, inside the main method type: |
01:49 | int n = minus 5; |
01:54 | We have created a variable 'n' to store the negative number. |
01:58 | Now we shall write the if conditions. |
02:01 | Next line, type: |
02:02 | if (n < 0) |
02:07 | open curly bracket. Press Enter. |
02:10 | System.out.println within brackets and double quotes Negative number; |
02:22 | We first see if the number is a negative number. |
02:25 | If yes, then we will not check for even and odd. |
02:29 | If the number is not a negative, we check for even and odd. |
02:34 | Next line, type:
else open curly bracket . Press Enter. |
02:42 | Now, if the execution has come to the else part. |
02:45 | It means that the number is non-negative. |
02:48 | So we check for odd or even inside this else part. |
02:52 | Type: |
02:53 | if within brackets n modulus 2 double equal to 0 open curly bracket press Enter. |
03:03 | System.out.println within brackets and double quotesEven number. |
03:13 | Then type the else part. else open curly braket, press Enter. |
03:18 | Type: System.out.println within brackets and double quotes Odd number semicolon. |
03:29 | So we make sure that negative numbers are not considered for odd or even check. |
03:34 | Now let us see the code in action. |
03:37 | Save and run the file. As we can see, we get the output as negative number. |
03:43 | Now let us try a positive number. |
03:46 | Change n = -5 to n = 5. |
03:53 | Now Save and Run the file. |
03:57 | As we can see, the output is odd number as expected. Let us try an even number. |
04:04 | Change n = 5 to n = 10. |
04:09 | Now Save and run the file. |
04:12 | As we can see, the output is even number as expected. |
04:17 | This process of including an if statement inside another, is called nested-if. |
04:22 | There is no limit to the amount of nesting. |
04:25 | But it is a good practice to not go beyond 3 levels of nesting. |
04:31 | Now we shall look at the ternary operator. |
04:33 | First let me clean up the main method. |
04:37 | We shall write a program that divides a number by 2. |
04:40 | It is a very trivial program but the issue comes in dividing odd numbers. |
04:45 | When 7 is divided by 2, we get 3. |
04:48 | But what if we want the result to be rounded off. |
04:50 | Which means, when 7 is divided by 2, we get 4 and not 3. |
04:56 | In simple terms, we need the next number. |
04:59 | Let us see how to write such a program. |
05:01 | See, inside the main method type: int n, nHalf semicolon |
05:08 | We will store the number in n and the half number in nHalf |
05:13 | Next line, type: n = 5 semicolon |
05:18 | Next line, type: if within bracket n modulus 2 == 0 open curly brackets Press Enter. |
05:28 | Type nHalf = n / 2 semicolon |
05:34 | In the else part, type: within curly brackets nHalf equal to within brackets n+1 the whole divided by 2 semicolon |
05:50 | We check if the number is even or odd and do the division accordingly. |
05:55 | Now Let us add a print statement to see the program in action. |
05:59 | So Type System.out.println within brackets nHalf semicolon |
06:11 | Now Save and Run the file. |
06:14 | As we can see, our objective is met. We get the output as 3 and not 2. |
06:21 | But if we notice, all we are doing is setting the value of a variable depending on a condition. |
06:27 | There is more syntax than logic in our program. |
06:31 | This is when ternary operator makes code simpler. |
06:35 | Ternary Operator is a conditional operator providing results similar to nested-if. |
06:40 | It Provides a short syntax and is denoted by a question mark. |
06:45 | It takes three operands at a time. |
06:48 | Let us learn about the syntax of Ternary Operator. |
06:53 | The expression is the condition that has to be checked. |
06:56 | Operand 1 is the value of the variable. Result if the condition is true. |
07:03 | Operand 2 is the value if the condition is false. |
07:09 | Now Let us use it in our program. |
07:12 | First, let us remove the if-else statement. |
07:17 | Type nHalf equal to n modulus 2 double equal to 0 question mark n / 2 colon within brackets n + 1 the whole divided by 2 semi-colon |
07:41 | This statement reads: |
07:43 | If 'n' is even, 'nHalf' is 'n by 2'. Otherwise it is 'n plus 1 by 2'. |
07:50 | Let us now see it in action. |
07:52 | Save and Runthe file. Press Ctrl S and Ctrl F11 keys. |
07:59 | As we can see, the output is as expected. |
08:02 | This way, ternary operator reduces clutter in the code and improves readability. |
08:09 | We have come to the end of this tutorial. |
08:11 | In this tutorial we have learnt: |
08:13 | * About Nested-If Statements and Ternary Operator |
08:15 | * Usage of Nested-If Statements and Ternary Operator in a Java program. |
08:22 | Now take an assignment on- |
08:23 | Nested-If and Ternary operator. Write java program for the following. |
08:28 | * Check whether a number is even and also a multiple of 11 using nested-if. |
08:34 | * Identify the largest number among the two given numbers using Ternary operator. |
08:40 | To know more about the Spoken Tutorial project, watch the video available at the following link. |
08:45 | It summarizes the spoken-tutorial project. If you do not have good bandwidth, you can download and watch it. |
08:52 | The Spoken Tutorial Project Team: |
08:54 | Conducts workshops using spoken tutorials and |
08:57 | gives certificates for those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org. |
09:07 | Spoken Tutorial Project is a part of the Talk to a Teacher project and |
09:11 | it is supported by the National mission on Education through ICT, MHRD, Government of India. |
09:17 | More information on this mission is available at spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro. |
09:26 | This script has been contributed by TalentSprint. This is Arya Ratish from IIT Bombay, signing off. Thanks for joining. |
Contributors and Content Editors
Arya Ratish, Devisenan, Krupali, PoojaMoolya, Priyacst, Sandhya.np14, Sneha