C-and-C++/C2/Nested-If-And-Switch-Statement/English-timed
From Script | Spoken-Tutorial
Time | Narration |
00:01 | Welcome to the spoken tutorial on Nested if & Switch statements in C and C++. |
00:07 | In this tutorial we will learn , |
00:09 | How to use nested if statement. And |
00:12 | switch statement. |
00:13 | We will do this with the help of some examples. |
00:17 | To record this tutorial, I am using, |
00:20 | Ubuntu operating system version 11.10 |
00:24 | gcc and g++ Compiler version 4.6.1 on Ubuntu. |
00:30 | First we will learn, how to write nested if and switch statement with an example. |
00:36 | I have already written the program |
00:39 | Let’s have a look |
00:40 | In this program ,we will learn to check the range of integers. |
00:45 | Note that our file name is nested-if.c |
00:50 | Let me explain the code now. |
00:52 | This is our Header file.
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00:54 | This is our main function.
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00:56 | Inside the main function we have declared two integer variables 'x and y' |
01:02 | Here we prompt the users to enter a number between the range of 0 to 39. |
01:08 | we take the value of y as input from the user. |
01:12 | This is our if condition |
01:14 | Here, we will check whether y/10=0 |
01:19 | If the condition is true |
01:20 | We print "you have entered a number in the range of 0-9. |
01:25 | This is our else-if condition. |
01:28 | Here we check that y/10=1. |
01:32 | If the condition is true. |
01:34 | We print you have entered a number in the range of 10-19. |
01:39 | In this else if condition we check whether the number is in the range of 20-29. |
01:45 | And here we will see that the number is in the range of 30 to 39. |
01:51 | This is our else condition.
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01:53 | If all of the above conditions are false |
02:24 | We print number not in range. |
02:28 | And this is our return statement |
02:31 | Now let us execute the program. |
02:35 | Please open the terminal window , by pressing Ctrl+Alt+T keys simultaneously on your keyboard. |
02:45 | To execute , Type “gcc” space “nested-if.c” space hyphen “-o” space “nested”. Press Enter |
02:57 | type dot slash “nested”. Press Enter |
03:01 | We see,Enter a number between 0 to 39. |
03:06 | I will Enter 12 |
03:09 | The output is displayed as: |
03:11 | you have entered the number in the range of 10-19. |
03:17 | Let us enter another number. |
03:21 | Let's execute again. Press the up arrow key, press enter. |
03:28 | I will give 5 this time. |
03:34 | We see the output as : |
03:35 | you have entered the number in the range of 0-9. |
03:42 | The conditional execution can also be done in another way. |
03:46 | By using switch statement. |
03:49 | Let’s see how it is done. |
03:51 | We will see the same program using switch. |
03:57 | I have already opened the program.
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03:59 | Let's switch back to our text editor |
04:07 | I have explained this in the previous program. |
04:11 | So i will move on to the Switch statements
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04:16 | Here, we divide the inputs i.e y by 10 and the result is stored in the variable x. |
04:24 | That means the quotient will be stored in x. |
04:28 | With the help of the quotient we can identify the range of the number. |
04:37 | Here, we tell the switch command that the variable to be checked is x. |
04:47 | This is case 0 . If case 0 is satisfied. |
04:50 | Then we print you have entered the number in the range of 0-9. |
04:58 | We add break to come out of the loop if the case is satisfied. |
05:03 | We need to break the loop each time. |
05:05 | It is because only one condition can be true at a time. |
05:11 | This is “case 1” . “case 1” means “if the value of x is 1”
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05:17 | We print you have entered a number in the range of 10-19. |
05:24 | This is “case 2” . |
05:26 | Here we print you have entered a number in the range of 20-29. |
05:33 | And this is case 3. Here we check whether the number is in the range of 30-39. |
05:43 | This is the default case. Default case specifies what needs to be done if none of the above cases are satisfied. |
05:52 | Here we print number not in range.
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05:57 | And This is our return statement. |
05:59 | Let us execute the program.
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06:02 | Switch back to the terminal. |
06:06 | Type:gcc switch.c -o switch. Press Enter |
06:16 | Type:./switch. Press Enter
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06:21 | Enter a number between of 0 to 39. I willl enter 35 |
06:28 | The output is displayed as,“you have entered the number in the range of 30 to 39”. |
06:35 | Now we will see how to execute the programs in C++. |
06:44 | Switch back to the text editor. |
06:47 | Note that our filename is nested-if.cpp |
06:55 | Here the logic and implementation are same |
06:59 | There are a few changes like: |
07:03 | The header file as iostream in place of stdio.h |
07:08 | Here we have included the using statement. |
07:11 | Using namespace std |
07:14 | And the cout and cin function in place of printf and scanf. |
07:23 | You can see that the rest of the code is similar to our C program. |
07:29 | Let’s execute the code. |
07:31 | Come back to the terminal. |
07:34 | Type: g++ nested-if.cpp -o nested1. Press Enter. |
07:45 | Type: ./nested1. Press Enter |
07:50 | enter a number between 0 and 39. I will enter 40. |
07:53 | The output is displayed as: “number not in range” |
08:06 | Now let’s see the switch program in C++ |
08:10 | Come back to the text editor. |
08:14 | Here also the logic and implementation are same. |
08:19 | You can see that the header file is iostream |
08:23 | Here is the using statement. |
08:25 | And we have changed the cout and cin function. |
08:33 | Rest of the code is similar to our switch.c program |
08:38 | Let us execute. |
08:40 | Come back to the terminal. |
08:42 | Type:g++ switch.cpp -o switch1 Press Enter |
08:52 | Type ./switch1. Press Enter |
08:57 | Enter a number between 0 and 39. |
09:00 | I will enter 25. |
09:04 | The output is displayed as: |
09:06 | “you have entered the number in the range of 20-29” |
09:11 | Now let us switch back to our slides. |
09:16 | We will see the comparison between switch and nested-if statement. |
09:21 | Switch statement is evaluated according to the result of the expression. |
09:28 | Netsed-if statement is run, only if the result of the expression is true. |
09:35 | In switch we treat various values of the variable as cases. |
09:41 | In nested-if we have to write the conditional statement for each value of the variable. |
09:49 | Switch statement can only check the integer values |
09:54 | Nested if can check for both integer and fractional values. |
10:00 | This brings us to the end of this tutorial. |
10:03 | Let us summarize. |
10:05 | In this tutorial we learnt, nested if statement.
Ex: else if( y/10==0) |
10:13 | switch statement.
e.g. Switch(x) |
10:16 | And Difference between nested-if and switch statements.
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10:22 | As an assignment, |
10:23 | Write a program to check whether the age of the employee is between 20 to 60. |
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11:13 | The script is contributed by Chaitanya Mokashi. This is Ashwini patil from IIT Bombay signing off. Thank you for joining. |
Contributors and Content Editors
Ashwini, Kavita salve, Krupali, PoojaMoolya, Pratik kamble, Priyacst, Sandhya.np14, Sneha