Difference between revisions of "C-and-C++/C3/Loops/English-timed"
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|'''Time''' | |'''Time''' | ||
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|'''Narration''' | |'''Narration''' | ||
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− | | 00 | + | | 00:01 |
− | |Welcome to the spoken tutorial on Loops in C and C++ | + | |Welcome to the spoken tutorial on '''Loops in C and C++'''. |
|- | |- | ||
− | | 00 | + | | 00:06 |
|In this tutorial we will learn, | |In this tutorial we will learn, | ||
|- | |- | ||
− | | 00 | + | | 00:09 |
− | |for loop, | + | |'''for loop,'''while loop''' and |
|- | |- | ||
− | | 00 | + | | 00:12 |
− | | | + | |'''do…while loop. ''' We will do this with the help of some examples. |
|- | |- | ||
− | | 00 | + | | 00:17 |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
|We will also see some common errors and their solutions. | |We will also see some common errors and their solutions. | ||
|- | |- | ||
− | | 00 | + | | 00:21 |
| To record this tutorial, I am using | | To record this tutorial, I am using | ||
|- | |- | ||
− | | 00 | + | | 00:24 |
− | |Ubuntu Operating System version 11.04 | + | |'''Ubuntu Operating System''' version 11.04, |
|- | |- | ||
− | |00 | + | |00:28 |
− | | gcc and g++ Compiler version 4.6.1 on Ubuntu. | + | | '''gcc''' and '''g++ Compiler''' version 4.6.1 on Ubuntu. |
− | + | ||
|- | |- | ||
− | |00 | + | |00:34 |
|Let us start with the introduction to loops. | |Let us start with the introduction to loops. | ||
|- | |- | ||
− | |00 | + | |00:38 |
|Loops are used to execute a group of instructions repeatedly. | |Loops are used to execute a group of instructions repeatedly. | ||
|- | |- | ||
− | | 00 | + | | 00:44 |
|Depending on the purpose they are divided into three types: | |Depending on the purpose they are divided into three types: | ||
|- | |- | ||
− | | 00 | + | | 00:48 |
− | |while loop | + | |'''while loop ''' '''do…..while loop''' and |
+ | |- | ||
+ | | 00:51 | ||
+ | |'''for loop '''Let us start with the '''while loop''' first. | ||
|- | |- | ||
− | | 00 | + | | 00:56 |
− | | | + | |A '''while loop''' tests the condition in the beginning. |
|- | |- | ||
− | | 00 | + | | 01:00 |
− | | | + | |The structure is: '''while''' ( condition ) |
|- | |- | ||
− | | | + | |01:03 |
− | | | + | |within the bracket '''statement block'''. |
|- | |- | ||
− | | | + | | 01:07 |
− | | | + | |Now move on to '''do….while loop '''. |
|- | |- | ||
− | | | + | | 01:09 |
− | | | + | |A '''do..while loop''' is executed '''at least once''' before the condition could be validated. |
|- | |- | ||
− | | 01 | + | | 01:15 |
− | | | + | |The structure is: |
|- | |- | ||
− | |01 | + | | 01:17 |
− | |within the | + | |'''do''' (within the brackets) statement block, |
|- | |- | ||
− | | 01 | + | |01:20 |
− | | | + | |after the bracket the '''while''' ( condition ). |
|- | |- | ||
− | | 01 | + | |01:23 |
− | | | + | |You can see that the condition is checked at the end. |
|- | |- | ||
− | | 01 | + | | 01:27 |
− | | | + | |Now,let us see an example on '''while loop''' and '''do...while loop '''. |
|- | |- | ||
− | | 01 | + | | 01:32 |
− | | | + | |I have already typed the code on the editor. |
+ | |- | ||
+ | | 01:35 | ||
+ | |Let me open it. | ||
|- | |- | ||
− | |01 | + | |01:37 |
− | | | + | |Note that our file name is '''while.c.'''. |
|- | |- | ||
− | |01 | + | |01:41 |
− | | | + | |Today we are going to learn addition of first 10 numbers using '''while''' loop. |
|- | |- | ||
− | | 01 | + | |01:47 |
− | | | + | |Let me explain the code now. |
|- | |- | ||
− | | 01 | + | |01:49 |
− | | | + | |This is our '''header file.''' |
|- | |- | ||
− | | 01 | + | | 01:51 |
− | | | + | |Inside the '''main()''' function we have declared two '''integer variables x''' and '''y '''and initialized to 0. |
|- | |- | ||
− | |01 | + | | 01:59 |
− | | | + | | This is our '''while loop.''' |
|- | |- | ||
− | | | + | | 02:02 |
− | | | + | | The condition of the '''while''' loop is '''x is less than or equal to 10. ''' |
|- | |- | ||
− | | | + | |02:06 |
− | | | + | |Here the value of '''x''' is added to the value of '''y.''' |
|- | |- | ||
− | | | + | | 02:10 |
− | | | + | | The value obtained after the addition is stored in '''y. ''' |
|- | |- | ||
− | | | + | | 02:15 |
− | | | + | | Then we print the value of y. |
+ | |- | ||
+ | | 02:18 | ||
+ | | Here ''' x '''is incremented. | ||
+ | |- | ||
+ | | 02:20 | ||
+ | | That means the variable '''x''' is increased by one. | ||
|- | |- | ||
− | | | + | | 02:25 |
− | | | + | |And this is our '''return''' statement. |
− | |||
|- | |- | ||
− | | 02 | + | | 02:27 |
− | | | + | |Now,let us execute the program. |
+ | |- | ||
+ | | 02:30 | ||
+ | | Please open the '''terminal''' window by pressing '''Ctrl, Alt''' and '''T''' keys simultaneously on your keyboard. | ||
|- | |- | ||
− | |02 | + | | 02:39 |
− | | | + | |Type '''gcc space while dot c space hyphen o space while ''' |
+ | |- | ||
+ | | 02:45 | ||
+ | |Press '''Enter'''. | ||
|- | |- | ||
− | | 02 | + | | 02:47 |
− | | | + | |Type '''./while ''' (dot slash while). Press Enter. |
|- | |- | ||
− | | 02 | + | | 02:52 |
− | | | + | | The output is displayed. |
|- | |- | ||
− | | 02 | + | | 02:54 |
− | | | + | | Now lets us see the working of ''' while loop.''' |
|- | |- | ||
− | | 02 | + | | 02:57 |
− | | | + | |Let me resize the window. |
|- | |- | ||
− | | | + | | 03:00 |
− | | | + | |Here, first the value of '''x ''' and '''y ''' is 0. |
|- | |- | ||
− | | | + | | 03:04 |
− | | | + | |This is our '''while ''' condition. |
|- | |- | ||
− | | | + | | 03:06 |
− | | | + | |Here we check whether x is less than or equal to 10 which means the values of x will be from 0 to 10. |
|- | |- | ||
− | | | + | | 03:15 |
− | | | + | |Then we add y plus x (i.e) 0 plus 0, we get 0. |
|- | |- | ||
− | | | + | | 03:22 |
− | | | + | | We print the value of y, here we get 0. |
+ | |- | ||
+ | | 03:27 | ||
+ | | Then x is incremented which means now the value of x will be 1. | ||
|- | |- | ||
− | | | + | | 03:33 |
− | | | + | |Then we will check the condition again, 1 is less than or equal to 10. If the condition is '''true ''' then we will add the values, |
+ | |- | ||
+ | | 03:44 | ||
+ | | y (i.e ) 0 plus x that is 1. 0 plus 1 is 1. | ||
|- | |- | ||
− | | | + | | 03:50 |
− | | | + | |We print the value as 1. |
|- | |- | ||
− | | | + | | 03:53 |
− | | | + | |Again x is incremented. |
|- | |- | ||
− | | | + | | 03:55 |
− | | | + | |Now the value of x is 2. |
|- | |- | ||
− | | 03 | + | | 03:59 |
− | | | + | |We check the condition again. |
− | + | ||
|- | |- | ||
− | | | + | | 04:01 |
− | | | + | |2 is less than or equal to 10, if the condition is '''true ''' then we will add the values, (i.e ) 1 plus 2 which will give 3. |
|- | |- | ||
− | | | + | | 04:11 |
− | | | + | |We print the value as 3. |
|- | |- | ||
− | | | + | | 04:13 |
− | | | + | |Like this, it will go on up to x is less than or equal to 10 (x<=10). |
|- | |- | ||
− | | | + | | 04:20 |
− | | | + | | Now, we will see the same program using '''do….while loop '''. |
|- | |- | ||
− | | | + | | 04:24 |
− | | | + | | Here is our program. |
|- | |- | ||
− | | 04 | + | | 04:26 |
− | | | + | |Note that our file name is '''do hyphen while dot c '''. |
+ | |||
|- | |- | ||
− | | 04 | + | | 04:31 |
− | | | + | |This part is already explained in the previous program. |
|- | |- | ||
− | | 04 | + | | 04:35 |
− | | | + | |So, let us move on to a '''do...while loop '''. |
|- | |- | ||
− | | 04 | + | | 04:38 |
− | | | + | |Here, first the body of the loop will be executed and then the condition is checked. |
|- | |- | ||
− | | 04 | + | | 04:44 |
− | | | + | |The value of x is added to the value of y and the value obtained after the addition is stored in y. |
|- | |- | ||
− | | 04 | + | | 04:52 |
− | | | + | |The logic is same as in '''while ''' program. |
|- | |- | ||
− | | 04 | + | | 04:55 |
− | | | + | |Now let us execute the program. |
|- | |- | ||
− | | 04 | + | | 04:58 |
− | | | + | |Come back to our terminal. |
|- | |- | ||
− | | | + | | 05:00 |
− | | | + | |Type '''gcc space do hyphen while dot c space hyphen o space do '''. Press '''Enter '''. |
|- | |- | ||
− | | 05 | + | | 05:08 |
− | |Type | + | |Type '''dot slash do '''(./do). Press '''Enter '''. |
|- | |- | ||
− | | 05 | + | | 05:12 |
− | | | + | |We can see that the output is similar to our '''while ''' program. |
|- | |- | ||
− | | 05 | + | | 05:16 |
− | | | + | |Now, let us see the working of '''do...while loop '''. |
|- | |- | ||
− | | 05 | + | | 05:20 |
− | | | + | |Let me resize the window. |
|- | |- | ||
− | | 05 | + | | 05:22 |
− | | | + | |Here the value x and y is 0. |
|- | |- | ||
− | | 05 | + | | 05:25 |
− | | | + | |We add those values. Then we will get 0. |
|- | |- | ||
− | | 05 | + | | 05:29 |
− | | | + | |Now the value of y is 0. |
|- | |- | ||
− | | 05 | + | | 05:31 |
− | | | + | |We print the value as 0. |
|- | |- | ||
− | | 05 | + | | 05:33 |
|Then x is incremented by 1 which means now the value of x is 1, then the condition will be checked. | |Then x is incremented by 1 which means now the value of x is 1, then the condition will be checked. | ||
|- | |- | ||
− | | 05 | + | | 05:42 |
− | | You can see that the body of loop is executed first | + | | You can see that the body of loop is executed first. |
|- | |- | ||
− | | 05 | + | | 05:45 |
− | | | + | | Anyhow, if the condition is '''false ''' then also we will get a value that is 0. |
+ | |- | ||
+ | | 05:52 | ||
+ | |Now, here we will check whether 1 is less than or equal to 10. | ||
|- | |- | ||
− | | 05 | + | | 05:56 |
− | |The condition is true | + | |The condition is true. Again we will add the values. |
|- | |- | ||
− | | 06 | + | | 06:00 |
− | | | + | | Now 0 plus 1. |
|- | |- | ||
− | | 06 | + | | 06:02 |
− | | | + | | Then we will print the value of y as 1. |
|- | |- | ||
− | | 06 | + | | 06:05 |
− | | | + | |Again x will be incremented. |
|- | |- | ||
− | | 06 | + | | 06:08 |
− | | | + | |Now the value of x is 2. |
|- | |- | ||
− | | 06 | + | | 06:11 |
− | | | + | |Then we check 2 is less than or equal to 10. |
|- | |- | ||
− | | 06 | + | | 06:15 |
− | | | + | |We will go back here. |
|- | |- | ||
− | | 06 | + | | 06:17 |
− | | | + | |Then we will add the values. 1 plus 2 is 3. |
|- | |- | ||
− | | 06 | + | | 06:20 |
− | | | + | | We print the value of y as 3. |
|- | |- | ||
− | | 06 | + | | 06:23 |
− | | | + | |Like this, the conditions will be checked till the value of x will be less than or equal to 10. |
|- | |- | ||
− | | 06 | + | | 06:30 |
− | | | + | |And this is our '''return''' statement. |
|- | |- | ||
− | | 06 | + | | 06:33 |
− | | | + | |Note that here the while condition ends with the semicolon. |
|- | |- | ||
− | | 06 | + | | 06:38 |
− | | | + | |In '''while loop''' the condition does not end with the semicolon. |
+ | |- | ||
+ | | 06:43 | ||
+ | |Now let us see how to execute these programs in C++. | ||
|- | |- | ||
− | | | + | | 06:48 |
− | | | + | |This is our while program in C++. |
|- | |- | ||
− | | | + | | 06:52 |
− | |The | + | |The logic and implementation are same as in our C program. |
|- | |- | ||
− | | | + | | 06:56 |
− | | | + | |There are a few changes like the header file as '''iostream''' in place of '''stdio.h'''. |
|- | |- | ||
− | | 07 | + | | 07:04 |
− | | | + | |We have included the 'using' statement here '''using namespace std''' and here we have used the '''cout''' function in place of '''printf ''' function. |
|- | |- | ||
− | | 07 | + | | 07:16 |
− | | | + | |The structure of '''while''' loop is same as in our C program. |
+ | |- | ||
+ | | 07:21 | ||
+ | |Lets us execute the program. | ||
|- | |- | ||
− | | 07 | + | | 07:23 |
− | | | + | |Come back to a terminal. |
|- | |- | ||
− | | 07 | + | | 07:25 |
− | | | + | |Let me clear the prompt. |
|- | |- | ||
− | | 07 | + | | 07:28 |
− | | | + | |To execute, type ''' g++ space while dot cpp space hyphen o space while1 '''. Press '''Enter '''. |
|- | |- | ||
− | | 07 | + | | 07:38 |
− | | | + | |Type '''dot slash while1 '''(./while1). Press '''Enter '''. |
|- | |- | ||
− | | 07 | + | | 07:43 |
− | | | + | |You can see that the output is similar to our while program in C. |
|- | |- | ||
− | | 07 | + | | 07:48 |
− | | | + | |Now let us see the '''do... while ''' program in C++. |
|- | |- | ||
− | | | + | | 07:52 |
− | | | + | |Come back to the text editor. |
|- | |- | ||
− | | | + | | 07:54 |
− | | | + | |Here also there are similar changes like the '''header file ''', the '''using statement ''' and the '''cout '''function. |
|- | |- | ||
− | | 08 | + | | 08:03 |
− | | | + | |Rest of the things are similar. |
|- | |- | ||
− | | 08 | + | | 08:06 |
− | | | + | |Lets us execute the program. |
|- | |- | ||
− | | 08 | + | | 08:08 |
− | | | + | |Come back to our terminal. |
|- | |- | ||
− | | 08 | + | | 08:10 |
− | | | + | |Type '''g++ space do hyphen while dot cpp space hyphen o space do1 '''. Press '''Enter '''. |
|- | |- | ||
− | | 08 | + | | 08:19 |
− | | | + | |Type '''dot slash do1 '''(./do1). Press '''Enter '''. |
|- | |- | ||
− | | 08 | + | | 08:23 |
− | | | + | |We can see that the output is similar to our '''do...while program in C. ''' |
|- | |- | ||
− | | 08 | + | | 08:28 |
− | | | + | |Now we will see some common errors and their solutions. |
|- | |- | ||
− | | 08 | + | | 08:32 |
− | | | + | |Come back to our text editor. |
|- | |- | ||
− | | | + | | 08:35 |
− | | | + | |Suppose, here I will not increment the value of x. |
+ | |- | ||
+ | | 08:41 | ||
+ | |Click on Save Let us see what happens. | ||
|- | |- | ||
− | | | + | | 08:44 |
− | | | + | |Come back to the terminal Let me clear the prompt. |
|- | |- | ||
− | | | + | | 08:47 |
− | | | + | |Lets us execute the program. |
|- | |- | ||
− | | | + | | 08:50 |
− | | | + | |Press the up-arrow key twice. |
+ | |- | ||
+ | | 08:54 | ||
+ | | Again press the up-arrow key. | ||
|- | |- | ||
− | | | + | | 08:57 |
− | | | + | |The output is displayed. |
|- | |- | ||
− | | | + | | 08:59 |
− | | | + | |We can see number of zeros, this is because the loop does not have the terminating condition . |
|- | |- | ||
− | | 09 | + | | 09:07 |
− | | | + | |It is known as '''infinite loop. ''' |
|- | |- | ||
− | | 09 | + | | 09:10 |
− | | | + | |'''Infinite loop ''' can cause the system to become unresponsive. |
+ | |- | ||
+ | | 09:14 | ||
+ | | It causes the program to consume all the '''processors time ''' but it can be terminated. | ||
|- | |- | ||
− | | 09 | + | | 09:21 |
− | | | + | |Come back to our program, let us fix the error. |
|- | |- | ||
− | | 09 | + | | 09:25 |
− | | | + | |Type '''x++ ''' and a semicolon. |
|- | |- | ||
− | | 09 | + | | 09:28 |
− | | | + | |Click on Save. Let us execute again. |
|- | |- | ||
− | | 09 | + | | 09:31 |
− | | | + | |Come back to terminal. |
|- | |- | ||
− | | 09 | + | | 09:33 |
− | | | + | |Press the up-arrow key. |
+ | |- | ||
+ | | 09:38 | ||
+ | |Yes, it is working. | ||
|- | |- | ||
− | | | + | | 09:40 |
− | | | + | |This brings us to the end of this tutorial. |
|- | |- | ||
− | | | + | | 09:43 |
− | | | + | |We will move back to our slides. |
|- | |- | ||
− | | | + | | 09:45 |
− | | | + | |Let us summarize. |
|- | |- | ||
− | | | + | | 09:47 |
− | | | + | |In this tutorial we learned, |
|- | |- | ||
− | | | + | | 09:50 |
− | | | + | | '''while loop ''' example. while(x is less than or equal to 10) |
|- | |- | ||
− | | | + | | 09:54 |
− | | | + | | '''do….while loop '''. |
|- | |- | ||
− | | | + | | 09:56 |
− | | | + | |example. do statement block and |
+ | |- | ||
+ | | 09:59 | ||
+ | |while condition at the end. | ||
+ | |- | ||
+ | | 10:01 | ||
+ | |As an assignment, | ||
+ | |- | ||
+ | | 10:03 | ||
+ | |write a program to print the following, using '''for''' loops. | ||
+ | |- | ||
+ | | 10:07 | ||
+ | |0 to 9. | ||
+ | |||
+ | |- | ||
+ | | 10:10 | ||
+ | |The syntax of the '''for loop ''' is | ||
+ | |||
+ | |- | ||
+ | |10:12 | ||
+ | |'''for (variable initialization; variable condition; and variable increment or decrement) ''' | ||
+ | |||
+ | |- | ||
+ | | 10:20 | ||
+ | |and here will be the body of the loop. | ||
|- | |- | ||
− | | 10 | + | | 10:24 |
− | |Watch the video available at the link shown below | + | |Watch the video available at the link shown below. |
|- | |- | ||
− | | 10 | + | | 10:27 |
− | |It summarizes the Spoken Tutorial project | + | |It summarizes the Spoken Tutorial project. |
|- | |- | ||
− | | 10 | + | | 10:30 |
− | |If you do not have good bandwidth, you can download and watch it | + | |If you do not have good bandwidth, you can download and watch it. |
|- | |- | ||
− | | 10 | + | | 10:33 |
− | |The Spoken Tutorial Project Team | + | |The Spoken Tutorial Project Team: |
|- | |- | ||
− | | 10 | + | | 10:35 |
− | |Conducts workshops using spoken tutorials | + | |Conducts workshops using spoken tutorials. |
|- | |- | ||
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− | |Gives certificates to those who pass an online test | + | |Gives certificates to those who pass an online test. |
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− | | 10 | + | | 10:42 |
− | |For more details, please write to | + | |For more details, please write to contact@spoken-tutorial.org. |
|- | |- | ||
− | | 10 | + | | 10:47 |
− | |Spoken Tutorial Project is a part of Talk to a Teacher project | + | |Spoken Tutorial Project is a part of Talk to a Teacher project. |
|- | |- | ||
− | | 10 | + | | 10:51 |
− | |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. |
|- | |- | ||
− | | | + | | 10:58 |
− | |More information on this | + | |More information on this mission is available at the link shown below. |
|- | |- | ||
− | | 11 | + | | 11:02 |
− | |This script as been contributed by Dhawal Goyal. This is Ashwini Patil from IIT Bombay signing off | + | |This script as been contributed by Dhawal Goyal. This is Ashwini Patil from IIT Bombay, signing off. |
|- | |- | ||
− | | 11 | + | | 11:08 |
|Thank You for joining. | |Thank You for joining. |
Latest revision as of 14:23, 24 March 2017
Time | Narration |
00:01 | Welcome to the spoken tutorial on Loops in C and C++. |
00:06 | In this tutorial we will learn, |
00:09 | for loop,while loop and |
00:12 | do…while loop. We will do this with the help of some examples. |
00:17 | We will also see some common errors and their solutions. |
00:21 | To record this tutorial, I am using |
00:24 | Ubuntu Operating System version 11.04, |
00:28 | gcc and g++ Compiler version 4.6.1 on Ubuntu. |
00:34 | Let us start with the introduction to loops. |
00:38 | Loops are used to execute a group of instructions repeatedly. |
00:44 | Depending on the purpose they are divided into three types: |
00:48 | while loop do…..while loop and |
00:51 | for loop Let us start with the while loop first. |
00:56 | A while loop tests the condition in the beginning. |
01:00 | The structure is: while ( condition ) |
01:03 | within the bracket statement block. |
01:07 | Now move on to do….while loop . |
01:09 | A do..while loop is executed at least once before the condition could be validated. |
01:15 | The structure is: |
01:17 | do (within the brackets) statement block, |
01:20 | after the bracket the while ( condition ). |
01:23 | You can see that the condition is checked at the end. |
01:27 | Now,let us see an example on while loop and do...while loop . |
01:32 | I have already typed the code on the editor. |
01:35 | Let me open it. |
01:37 | Note that our file name is while.c.. |
01:41 | Today we are going to learn addition of first 10 numbers using while loop. |
01:47 | Let me explain the code now. |
01:49 | This is our header file. |
01:51 | Inside the main() function we have declared two integer variables x and y and initialized to 0. |
01:59 | This is our while loop. |
02:02 | The condition of the while loop is x is less than or equal to 10. |
02:06 | Here the value of x is added to the value of y. |
02:10 | The value obtained after the addition is stored in y. |
02:15 | Then we print the value of y. |
02:18 | Here x is incremented. |
02:20 | That means the variable x is increased by one. |
02:25 | And this is our return statement. |
02:27 | Now,let us execute the program. |
02:30 | Please open the terminal window by pressing Ctrl, Alt and T keys simultaneously on your keyboard. |
02:39 | Type gcc space while dot c space hyphen o space while |
02:45 | Press Enter. |
02:47 | Type ./while (dot slash while). Press Enter. |
02:52 | The output is displayed. |
02:54 | Now lets us see the working of while loop. |
02:57 | Let me resize the window. |
03:00 | Here, first the value of x and y is 0. |
03:04 | This is our while condition. |
03:06 | Here we check whether x is less than or equal to 10 which means the values of x will be from 0 to 10. |
03:15 | Then we add y plus x (i.e) 0 plus 0, we get 0. |
03:22 | We print the value of y, here we get 0. |
03:27 | Then x is incremented which means now the value of x will be 1. |
03:33 | Then we will check the condition again, 1 is less than or equal to 10. If the condition is true then we will add the values, |
03:44 | y (i.e ) 0 plus x that is 1. 0 plus 1 is 1. |
03:50 | We print the value as 1. |
03:53 | Again x is incremented. |
03:55 | Now the value of x is 2. |
03:59 | We check the condition again. |
04:01 | 2 is less than or equal to 10, if the condition is true then we will add the values, (i.e ) 1 plus 2 which will give 3. |
04:11 | We print the value as 3. |
04:13 | Like this, it will go on up to x is less than or equal to 10 (x<=10). |
04:20 | Now, we will see the same program using do….while loop . |
04:24 | Here is our program. |
04:26 | Note that our file name is do hyphen while dot c . |
04:31 | This part is already explained in the previous program. |
04:35 | So, let us move on to a do...while loop . |
04:38 | Here, first the body of the loop will be executed and then the condition is checked. |
04:44 | The value of x is added to the value of y and the value obtained after the addition is stored in y. |
04:52 | The logic is same as in while program. |
04:55 | Now let us execute the program. |
04:58 | Come back to our terminal. |
05:00 | Type gcc space do hyphen while dot c space hyphen o space do . Press Enter . |
05:08 | Type dot slash do (./do). Press Enter . |
05:12 | We can see that the output is similar to our while program. |
05:16 | Now, let us see the working of do...while loop . |
05:20 | Let me resize the window. |
05:22 | Here the value x and y is 0. |
05:25 | We add those values. Then we will get 0. |
05:29 | Now the value of y is 0. |
05:31 | We print the value as 0. |
05:33 | Then x is incremented by 1 which means now the value of x is 1, then the condition will be checked. |
05:42 | You can see that the body of loop is executed first. |
05:45 | Anyhow, if the condition is false then also we will get a value that is 0. |
05:52 | Now, here we will check whether 1 is less than or equal to 10. |
05:56 | The condition is true. Again we will add the values. |
06:00 | Now 0 plus 1. |
06:02 | Then we will print the value of y as 1. |
06:05 | Again x will be incremented. |
06:08 | Now the value of x is 2. |
06:11 | Then we check 2 is less than or equal to 10. |
06:15 | We will go back here. |
06:17 | Then we will add the values. 1 plus 2 is 3. |
06:20 | We print the value of y as 3. |
06:23 | Like this, the conditions will be checked till the value of x will be less than or equal to 10. |
06:30 | And this is our return statement. |
06:33 | Note that here the while condition ends with the semicolon. |
06:38 | In while loop the condition does not end with the semicolon. |
06:43 | Now let us see how to execute these programs in C++. |
06:48 | This is our while program in C++. |
06:52 | The logic and implementation are same as in our C program. |
06:56 | There are a few changes like the header file as iostream in place of stdio.h. |
07:04 | We have included the 'using' statement here using namespace std and here we have used the cout function in place of printf function. |
07:16 | The structure of while loop is same as in our C program. |
07:21 | Lets us execute the program. |
07:23 | Come back to a terminal. |
07:25 | Let me clear the prompt. |
07:28 | To execute, type g++ space while dot cpp space hyphen o space while1 . Press Enter . |
07:38 | Type dot slash while1 (./while1). Press Enter . |
07:43 | You can see that the output is similar to our while program in C. |
07:48 | Now let us see the do... while program in C++. |
07:52 | Come back to the text editor. |
07:54 | Here also there are similar changes like the header file , the using statement and the cout function. |
08:03 | Rest of the things are similar. |
08:06 | Lets us execute the program. |
08:08 | Come back to our terminal. |
08:10 | Type g++ space do hyphen while dot cpp space hyphen o space do1 . Press Enter . |
08:19 | Type dot slash do1 (./do1). Press Enter . |
08:23 | We can see that the output is similar to our do...while program in C. |
08:28 | Now we will see some common errors and their solutions. |
08:32 | Come back to our text editor. |
08:35 | Suppose, here I will not increment the value of x. |
08:41 | Click on Save Let us see what happens. |
08:44 | Come back to the terminal Let me clear the prompt. |
08:47 | Lets us execute the program. |
08:50 | Press the up-arrow key twice. |
08:54 | Again press the up-arrow key. |
08:57 | The output is displayed. |
08:59 | We can see number of zeros, this is because the loop does not have the terminating condition . |
09:07 | It is known as infinite loop. |
09:10 | Infinite loop can cause the system to become unresponsive. |
09:14 | It causes the program to consume all the processors time but it can be terminated. |
09:21 | Come back to our program, let us fix the error. |
09:25 | Type x++ and a semicolon. |
09:28 | Click on Save. Let us execute again. |
09:31 | Come back to terminal. |
09:33 | Press the up-arrow key. |
09:38 | Yes, it is working. |
09:40 | This brings us to the end of this tutorial. |
09:43 | We will move back to our slides. |
09:45 | Let us summarize. |
09:47 | In this tutorial we learned, |
09:50 | while loop example. while(x is less than or equal to 10) |
09:54 | do….while loop . |
09:56 | example. do statement block and |
09:59 | while condition at the end. |
10:01 | As an assignment, |
10:03 | write a program to print the following, using for loops. |
10:07 | 0 to 9. |
10:10 | The syntax of the for loop is |
10:12 | for (variable initialization; variable condition; and variable increment or decrement) |
10:20 | and here will be the body of the loop. |
10:24 | Watch the video available at the link shown below. |
10:27 | It summarizes the Spoken Tutorial project. |
10:30 | If you do not have good bandwidth, you can download and watch it. |
10:33 | The Spoken Tutorial Project Team: |
10:35 | Conducts workshops using spoken tutorials. |
10:38 | Gives certificates to those who pass an online test. |
10:42 | For more details, please write to contact@spoken-tutorial.org. |
10:47 | Spoken Tutorial Project is a part of Talk to a Teacher project. |
10:51 | It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
10:58 | More information on this mission is available at the link shown below. |
11:02 | This script as been contributed by Dhawal Goyal. This is Ashwini Patil from IIT Bombay, signing off. |
11:08 | Thank You for joining. |