Difference between revisions of "Java/C2/Nested-if/English-timed"
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| '''Time''' | | '''Time''' | ||
|'''Narration''' | |'''Narration''' | ||
+ | |||
|- | |- | ||
| 00:02 | | 00:02 | ||
| Welcome to the spoken tutorial on '''Nested-If and Ternary Operator''' in java. | | 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: | | By the end of this tutorial you should be able to: | ||
Explain '''Nested-If''' Statements and '''Ternary operators''' and | Explain '''Nested-If''' Statements and '''Ternary operators''' and | ||
Use them in a Java program. | Use them in a Java program. | ||
+ | |||
|- | |- | ||
− | | 00:17 | + | |00:17 |
− | + | |For this tutorial we are using: | |
'''Ubuntu v 11.10,''' | '''Ubuntu v 11.10,''' | ||
'''JDK 1.6,''' and | '''JDK 1.6,''' and | ||
'''EclipseIDE 3.7.0''' | '''EclipseIDE 3.7.0''' | ||
+ | |||
|- | |- | ||
− | | | + | | 00:27 |
| To follow this tutorial, you should know | | To follow this tutorial, you should know | ||
|- | |- | ||
− | | | + | | 00:29 |
|about the usage of '''relational''' and '''logical operators''' | |about the usage of '''relational''' and '''logical operators''' | ||
|- | |- | ||
− | | | + | |00:33 |
|and '''if...else''' '''control flow''' statements. | |and '''if...else''' '''control flow''' statements. | ||
|- | |- | ||
− | | | + | |00:36 |
|If not, for relevant tutorials, please visit our website which is as shown. | |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 | + | |00:49 |
− | + | |Now let us look at the syntax for writing the '''Nested-If statement'''. | |
|- | |- | ||
− | | | + | |00:53 |
|In this case, if '''condition1''' is true, then the program checks for '''condition2'''. | |In this case, if '''condition1''' is true, then the program checks for '''condition2'''. | ||
|- | |- | ||
− | | | + | |00:59 |
|Condition 2 is given using another '''if''' statement. | |Condition 2 is given using another '''if''' statement. | ||
|- | |- | ||
− | | | + | |01:03 |
| If '''condition2''' is true then the program executes '''Statement or block 1'''. | | If '''condition2''' is true then the program executes '''Statement or block 1'''. | ||
|- | |- | ||
− | | | + | | 01:09 |
|Else, it executes '''Statement or block 2'''. | |Else, it executes '''Statement or block 2'''. | ||
|- | |- | ||
− | | | + | | 01:13 |
|If '''condition1''' is false then the program will not check '''condition2'''. | |If '''condition1''' is false then the program will not check '''condition2'''. | ||
|- | |- | ||
− | | | + | | 01:18 |
|Instead it will directly jump to its '''else''' statement i.e. block 3. | |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. | |We have created a class '''NesedIfDemo''' and added the '''main method''' to it. | ||
Line 82: | Line 86: | ||
|- | |- | ||
− | | | + | | 01:42 |
− | | | + | | we will also handle negative numbers using a '''nested-if'''. |
|- | |- | ||
Line 90: | Line 94: | ||
|- | |- | ||
− | | | + | | 01:49 |
|'''int n''' = minus '''5;''' | |'''int n''' = minus '''5;''' | ||
|- | |- | ||
− | | | + | |01:54 |
|We have created a variable 'n' to store the negative number. | |We have created a variable 'n' to store the negative number. | ||
|- | |- | ||
− | | | + | |01:58 |
|Now, we shall write the '''if''' conditions. | |Now, we shall write the '''if''' conditions. | ||
|- | |- | ||
− | | | + | |02:01 |
− | | | + | |Next line, type: '''if (n < 0) ''' |
|- | |- | ||
− | | | + | | 02:07 |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
|open curly bracket. Press Enter. | |open curly bracket. Press Enter. | ||
|- | |- | ||
− | | | + | | 02:10 |
|'''System.out.println''' within brackets and double quotes '''Negative number'''; | |'''System.out.println''' within brackets and double quotes '''Negative number'''; | ||
|- | |- | ||
− | | | + | | 02:22 |
|We first see if the number is a negative number. | |We first see if the number is a negative number. | ||
Line 126: | Line 126: | ||
|- | |- | ||
− | | | + | | 02:29 |
− | | | + | | If the number is not a negative, we check for 'even' and 'odd'. |
|- | |- | ||
− | | | + | | 02:34 |
− | | Next line, type: | + | | Next line, type:'''else''' open curly bracket. Press Enter. |
− | + | ||
− | '''else''' open curly bracket | + | |
|- | |- | ||
Line 144: | Line 142: | ||
|- | |- | ||
− | | | + | | 02:48 |
|So, we check for odd or even inside this '''else''' part. | |So, we check for odd or even inside this '''else''' part. | ||
|- | |- | ||
− | | | + | | 02:52 |
− | | Type: | + | | Type:'''if''' within brackets '''n modulus 2''' double equal to '''0''' open curly bracket press Enter. |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
|- | |- | ||
− | | | + | | 03:03 |
|'''System.out.println ''' within brackets and double quotes '''Even number'''; | |'''System.out.println ''' within brackets and double quotes '''Even number'''; | ||
|- | |- | ||
− | | | + | | 03:13 |
|Then type the '''else''' part. '''else''' open curly braket, press Enter. | |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. | | 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. | |So, we make sure that negative numbers are not considered for 'odd' or 'even' check. | ||
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|- | |- | ||
− | | | + | | 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. | |Now let us try a positive number. | ||
|- | |- | ||
− | | | + | | 03:46 |
− | | | + | | Change '''n = -5''' to '''n = 5'''. |
|- | |- | ||
− | | | + | |03:53 |
|Now '''Save''' and''' Run''' the file. | |Now '''Save''' and''' Run''' the file. | ||
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|- | |- | ||
− | | | + | |04:25 |
|But it is a good practice to not go beyond 3 levels of nesting. | |But it is a good practice to not go beyond 3 levels of nesting. | ||
|- | |- | ||
− | | | + | |04:31 |
− | | Now we shall look at the '''ternary operator'''. | + | |Now we shall look at the '''ternary operator'''. |
|- | |- | ||
− | | | + | |04:33 |
|First, let me clean up the '''main method'''. | |First, let me clean up the '''main method'''. | ||
|- | |- | ||
− | | 04:37 | + | |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. | |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. | |When 7 is divided by 2, we get 3. | ||
|- | |- | ||
− | | | + | |04:48 |
|But what if we want the result to be rounded off. | |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. | |Which means, when 7 is divided by 2, we get 4 and not 3. | ||
Line 253: | Line 247: | ||
|- | |- | ||
| 04:59 | | 04:59 | ||
− | | | + | | Let us see how to write such a program.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''' | |We will store the number in '''n''' and the half number in '''nHalf''' | ||
Line 288: | Line 278: | ||
|- | |- | ||
− | | | + | | 05:59 |
| So, type '''System.out.println''' within brackets '''nHalf''' semicolon'''. | | So, type '''System.out.println''' within brackets '''nHalf''' semicolon'''. | ||
+ | |||
|- | |- | ||
− | | | + | | 06:11 |
|Now '''Save''' and '''Run''' the file. | |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. | |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. | | 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. | |There is more syntax than '''logic''' in our program. | ||
|- | |- | ||
− | | | + | |06:31 |
|This is when '''ternary operator''' makes code simpler. | |This is when '''ternary operator''' makes code simpler. | ||
|- | |- | ||
− | | | + | | 06:35 |
| '''Ternary Operator''' is a '''conditional''' operator providing results similar to '''nested-if'''. | | '''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. | |It Provides a short syntax and is denoted by a question mark. | ||
|- | |- | ||
− | | | + | |06:45 |
| It takes three '''operands''' at a time. | | 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. | |The '''Expression''' is the condition that has to be checked. | ||
Line 363: | Line 354: | ||
|- | |- | ||
− | | | + | | 07:52 |
|'''Save''' and '''Run'''the file. Press '''Ctrl S''' and '''Ctrl F11''' keys. | |'''Save''' and '''Run'''the file. Press '''Ctrl S''' and '''Ctrl F11''' keys. | ||
Line 383: | Line 374: | ||
|- | |- | ||
− | | | + | | 08:13 |
| About '''Nested-If Statements''' and '''Ternary Operator''' and | | About '''Nested-If Statements''' and '''Ternary Operator''' and | ||
+ | |||
|- | |- | ||
− | | | + | | 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. | ||
|- | |- | ||
|08:22 | |08:22 | ||
− | |Now take an assignment on | + | |Now take an assignment on '''Nested-If''' and '''Ternary operator'''. Write java program for the following. |
|- | |- | ||
− | |08: | + | | 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'''. | |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. | | 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: | |The Spoken Tutorial Project team: | ||
+ | |||
|- | |- | ||
− | | | + | |08:54 |
|Conducts workshops using spoken tutorials and | |Conducts workshops using spoken tutorials and | ||
+ | |||
|- | |- | ||
− | | | + | |08:57 |
|gives certificates to those who pass an online test. For more details, please write to '''contact AT spoken HYPHEN tutorial DOT org.''' | |gives certificates to 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 | + | |Spoken Tutorial Project is a part of the Talk to a Teacher project and |
+ | |||
|- | |- | ||
− | | 09:11 | + | |09:11 |
|it is supported by the National mission on Education through ICT, MHRD, Government of India. | |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'''. | |More information on this mission is available at '''spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro'''. | ||
|- | |- | ||
| 09:26 | | 09:26 | ||
− | | | + | | This script has been contributed by TalentSprint. This is Arya Ratish from IIT Bombay, signing off. Thanks for joining. |
|} | |} |
Latest revision as of 15:25, 9 March 2017
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:
Explain Nested-If Statements and Ternary operators and Use them in a Java program. |
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 condition1 is true, then the program checks for condition2. |
00:59 | Condition 2 is given using another if statement. |
01:03 | If condition2 is true then the program executes Statement or block 1. |
01:09 | Else, it executes Statement or block 2. |
01:13 | If condition1 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 an 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: 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:if within brackets n modulus 2 double equal to 0 open curly bracket press Enter. |
03:03 | System.out.println within brackets and double quotes Even 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.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 semicolon. |
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 and |
08:15 | Usage of Nested-If Statements and Ternary Operator in a Java program. |
08:22 | Now take an assignment on 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 to 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