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{| border=1
 
{| border=1
|| ''Time'''
+
|| Time
|| '''Narration''
+
|| Narration
  
 
|-
 
|-
|  00.02
+
|  00:02
|  Welcome to the spoken tutorial on '''Conditional statements in C and C++'''
+
|  Welcome to the spoken tutorial on '''Conditional statements in C and C++'''.
  
 
|-
 
|-
|  00.09
+
|  00:08
|  In this tutorial we will learn,
+
|  In this tutorial we will learn:
 
+
  
 
|-
 
|-
|  00.11
+
|  00:11
| how to execute a single '''statement'''.
+
| How to execute a single '''statement'''
 
+
  
 
|-
 
|-
|  00.14
+
|  00:14
 
| How to execute group of '''statements'''.
 
| How to execute group of '''statements'''.
 
  
 
|-
 
|-
|  00.17
+
|  00:16
 
| We will do this through examples.
 
| We will do this through examples.
 
  
 
|-
 
|-
|  00.20
+
|  00:19
 
| We will also see some common errors and their solutions.
 
| We will also see some common errors and their solutions.
  
 
|-
 
|-
|  00.25
+
|  00:25
|  To record this tutorial, I am using, '''Ubuntu Operating system''' version 11.10.
+
|  To record this tutorial, I am using '''Ubuntu Operating system''' version 11.10.
 
+
  
 
|-
 
|-
|  00.32
+
|  00:31
| '''gcc''' and '''g++ Compiler''' version 4.6.1  
+
| '''gcc''' and '''g++ Compiler''' version 4.6.1.
  
 
|-
 
|-
| 00.38
+
| 00:38
| Let us start with the Introduction to condition '''statements'''.  
+
| Let us start with the introduction to conditional '''statements'''.  
 
+
  
 
|-
 
|-
|  00.43  
+
|  00:43  
 
| A '''statement''' in a program controls the flow of program execution.
 
| A '''statement''' in a program controls the flow of program execution.
 
  
 
|-
 
|-
|  00.50 
+
|  00:49
| It helps to make decision on, what code is to be executed.
+
| It helps to make decision on what code is to be executed.
 
+
  
 
|-
 
|-
|  00.56
+
|  00:55
 
|We can check the conditions, whether true or false.
 
|We can check the conditions, whether true or false.
 
  
 
|-
 
|-
|  01.01
+
|  01:00
 
| We can execute a single statement or a group of statements.
 
| We can execute a single statement or a group of statements.
  
 
|-
 
|-
| 01.08
+
| 01:07
| Let us understand the flow of if statements.
+
| Let us understand the flow of '''if''' statements.
 
+
  
 
|-
 
|-
|  01.13
+
|  01:13
| Here, if the condition is true then , '''statement1''' will be executed.
+
| Here, if the condition is true then '''statement 1''' will be executed.
 
+
  
 
|-
 
|-
|  01.20
+
|  01:20
| If the condition is false then '''statement2''' will be executed.  
+
| If the condition is false then '''statement 2''' will be executed.  
  
 
|-
 
|-
|  01.29
+
|  01:29
|   Now we will see the flow of else if '''statement''',
+
| Now we will see the flow of '''else if''' statement.
 
+
  
 
|-
 
|-
|  01.32
+
|  01:32
| Here, if '''condition1''' is true then '''statement1''' will be executed.
+
| Here, if '''condition 1''' is true then '''statement 1''' will be executed.
 
+
  
 
|-
 
|-
|  01.41
+
|  01:41
| If '''condition1''' is false then it will check for another condition that is '''condition2'''.
+
| If '''condition 1''' is false then it will check for another condition that is '''condition 2'''.
 
+
  
 
|-
 
|-
|  01.50
+
|  01:49
| If '''condition2''' is true, then '''statement3''' will be executed.
+
| If '''condition 2''' is true then '''statement 3''' will be executed.
 
+
  
 
|-
 
|-
|  01.55
+
|  01:54
| And If '''condition2''' is false, then '''statement2''' will be executed
+
| And If '''condition 2''' is false then '''statement 2''' will be executed.
  
 
|-
 
|-
|  02.03
+
|  02:02
 
|  Now Let us move on to our program.
 
|  Now Let us move on to our program.
 
  
 
|-
 
|-
|  02.06
+
|  02:06
 
| I have already typed the code on the editor.
 
| I have already typed the code on the editor.
 
  
 
|-
 
|-
|  02.09  
+
|  02:09  
| So let me open it.
+
| So, let me open it.
 
+
  
 
|-
 
|-
|  02.13
+
|  02:13
| Note that our filename is '''ifstmt.c'''
+
| Note that our file name is '''ifstmt.c'''.
  
 
|-
 
|-
|  02.19
+
|  02:18
 
| In this program we will calculate the sum of two numbers and will check a few conditions.
 
| In this program we will calculate the sum of two numbers and will check a few conditions.
  
 
|-
 
|-
|  02.27
+
|  02:26
 
|  Let me explain the code now.  
 
|  Let me explain the code now.  
 
  
 
|-
 
|-
|  02.31
+
|  02:30
 
| This is our '''header file.'''
 
| This is our '''header file.'''
  
 
|-
 
|-
|  02.34
+
|  02:34
|  This is our '''main function.'''
+
|  This is our '''main()''' function.
  
 
|-
 
|-
| 02.38  
+
| 02:38  
|  Here we have declared three integer '''variables''' '''a, b and sum.'''
+
|  Here we have declared three '''integer variables''' '''a, b''' and '''sum.'''
  
 
|-
 
|-
|  02.47
+
|  02:46
|   Here we are asking for user input.
+
| Here we are asking for user input.
 
+
  
 
|-
 
|-
|  02.49
+
|  02:49
 
| User will enter the values of a and b.  
 
| User will enter the values of a and b.  
 
  
 
|-
 
|-
|  02.52
+
|  02:52
 
| The values will be stored in '''variable a''' and '''variable b.'''
 
| The values will be stored in '''variable a''' and '''variable b.'''
  
 
|-
 
|-
|  02.58
+
|  02:58
|The 'scanf()''' reads data from the '''console.'''
+
|The '''scanf()''' function reads data from the console.
 
+
  
 
|-
 
|-
|  03.02
+
|  03:02
 
| It then stores the result in the given '''variable.'''
 
| It then stores the result in the given '''variable.'''
 
  
 
|-
 
|-
|  03.06
+
|  03:06
| The''' format specifier '''in the''' scanf() '''helps to know the type of data.
+
| The '''format specifier''' in the '''scanf()''' helps to know the type of data.
 
+
  
 
|-
 
|-
|  03.11
+
|  03:10
| Like here we have %d it denotes that we are dealing with integer data type.
+
| Like here we have '''%d''', it denotes that we are dealing with integer data type.
  
 
|-
 
|-
|  03.19
+
|  03:18
|  Here we add the values of''' a''' and '''b.'''
+
|  Here we add the values of '''a''' and '''b.'''
 
+
  
 
|-
 
|-
| 03.22
+
| 03:22
 
| We will store the result in '''sum.'''
 
| We will store the result in '''sum.'''
  
 
|-
 
|-
|  03.26
+
|  03:25
 
|  Then we print the result.
 
|  Then we print the result.
  
 
|-
 
|-
|  03.29
+
|  03:29
|  This is our '''if statement.'''  
+
|  This is our '''if''' statement.
  
 
|-
 
|-
|  03.31
+
|  03:30
 
|Here, we check the condition whether '''sum''' is greater than 20.
 
|Here, we check the condition whether '''sum''' is greater than 20.
  
 
|-
 
|-
|  03.36
+
|  03:36
 
|If the condition is true, then we print '''Sum''' is greater than 20.
 
|If the condition is true, then we print '''Sum''' is greater than 20.
  
 
|-
 
|-
|  03.43
+
|  03:42
|  Now let me comment out these lines.
+
|  Now let me comment out these lines.
  
 
|-
 
|-
|03.48
+
|03:48
|This is our return statement.
+
|This is our '''return''' statement.
  
 
|-
 
|-
|  03.51
+
|  03:51
| Now click on '''Save'''  
+
| Now click on '''Save'''.
  
 
|-
 
|-
|  03.53
+
|  03:53
|First we will see the execution of if statement.
+
|First we will see the execution of '''if''' statement.
  
 
|-
 
|-
|  03.58
+
|  03:58
|   Please open the terminal window by pressing,'''Ctrl, Alt and T''' keys simultaneously on your keyboard.
+
| Please open the terminal window by pressing '''Ctrl, Alt''' and '''T''' keys simultaneously on your keyboard.
  
 
|-
 
|-
|04.09
+
|04:09
| To compile   type, '''gcc ifstmt.c -o if'''and press enter
+
| To compile, type '''gcc space ifstmt dot c space  -o space if''' and press Enter.
  
 
|-
 
|-
| 04.20
+
| 04:20
|   To execute  type, '''./if''' press enter
+
| To execute, type '''./if''' (dot slash if). Press Enter.
  
 
|-
 
|-
| 04.26
+
| 04:26
it is displayed as,
+
It is displayed as '''Enter the values of a and b'''.
  
 
|-
 
|-
|  04.27
+
|  04:31
|Enter the value of a and b.
+
 
+
|-
+
|  04.32
+
 
|I will give the values as 10 and 12.
 
|I will give the values as 10 and 12.
  
 
|-
 
|-
|  04.38
+
|  04:38
|The output is displayed as Sum of a and b is 22. Sum is greater than 20.
+
|The output is displayed as '''Sum of a and b is 22. Sum is greater than 20'''.
  
 
|-
 
|-
| 04.45
+
| 04:45
 
|  Now come back to our program.
 
|  Now come back to our program.
  
 
|-
 
|-
|  04.49
+
|  04:48
|   We will check another condition.
+
| We will check another condition.
  
 
|-
 
|-
|  04.53
+
|  04:52
 
|Let me remove the comment from here.
 
|Let me remove the comment from here.
  
 
|-
 
|-
|  04.57
+
|  04:56
 
|I will give the comment here.
 
|I will give the comment here.
  
 
|-
 
|-
|  05.00
+
|  05:00
|Now click on '''Save.'''
+
|Now click on '''Save.''' This is our '''else-if''' statement.
  
 
|-
 
|-
|  05.03
+
|  05:05
| This is our else-if statement.  
+
|Here, we check another condition whether '''Sum''' is greater than 10.
  
 
|-
 
|-
|  05.05
+
|  05:11
|Here, we check another condition whether  '''Sum''' is greater than 10
+
|If the condition is true then we print 'Sum is greater than 10 and less than 20'.
  
 
|-
 
|-
| 05.11
+
| 05:18
|If the condition is true. Then we print '''Sum''' is greater than 10 and less than 20.
+
 
+
|-
+
| 05.18
+
 
|  Now come back to our terminal.
 
|  Now come back to our terminal.
  
 
|-
 
|-
|  05.20
+
|  05:20
|Let us compile as before. Let us execute as before.
+
|Let us compile as before.  
 +
|-
 +
|  05:23
 +
|Let us execute as before.
  
 
|-
 
|-
|  05.27
+
|  05:26
| It is displayed as,
+
| It is displayed as
  
 
|-
 
|-
|  05.28
+
|  05:28
|Enter the value of a and b.
+
|'''Enter the value of a and b'''.
 
|-
 
|-
|  05.30
+
|  05:30
 
| I will give the values as 10 and 2.
 
| I will give the values as 10 and 2.
  
 
|-
 
|-
|  05.35
+
|  05:35
|The output is displayed as: Sum of a and b is 12.  
+
|The output is displayed as: '''Sum of a and b is 12'''.  
  
 
|-
 
|-
|  05.39
+
|  05:38
|Sum is greater than 10 and less than 20.
+
|'''Sum is greater than 10 and less than 20'''.
  
 
|-
 
|-
| 05.43
+
| 05:42
|Let me clear the prompt.  Now come back to our program.
+
|Let me clear the prompt.  
  
 
|-
 
|-
| 05.48
+
| 05:44
| I will remove the comment from here and here.Now click on  save,
+
| Now come back to our program.
  
 
|-
 
|-
|  05.56
+
|  05:48
|   If both the above conditions are false, then we print Sum is less than 10.
+
| I will remove the comment from here and here. Now click on Save.
  
 
|-
 
|-
06.04
+
05:56
|This is our else statement.
+
| If both the above conditions are false then we print 'Sum is less than 10'.
  
 
|-
 
|-
|  06.08
+
|  06:04
| Now let us execute and see.  come back to our terminal.
+
|This is our '''else''' statement.
  
 
|-
 
|-
| 06.12
+
| 06:07
|Let us compile as before. Let us execute as before.
+
| Now let us execute and see. Come back to our terminal.
  
 
|-
 
|-
| 06.18
+
| 06:11
| | Here it is displayed as,
+
|Let us compile as before. Let us execute as before.
  
 
|-
 
|-
|  06.19
+
|  06:18
|Enter the value of a and b.
+
| Here it is displayed as '''Enter the value of a and b'''.
  
 
|-
 
|-
|  06.22
+
|  06:22
 
|I will give the values as 3 and 5.
 
|I will give the values as 3 and 5.
  
 
|-
 
|-
|  06.27
+
|  06:27
| the output is assum of a and b is 8.  
+
| The output is displayed as '''sum of a and b is 8'''.  
  
 
|-
 
|-
|  06.31
+
|  06:31
|Sum is less than 10.
+
|'''Sum is less than 10'''.
  
 
|-
 
|-
|  06.34
+
|  06:34
 
|  Now we will see some common errors which we can come across.
 
|  Now we will see some common errors which we can come across.
  
 
|-
 
|-
|  06.38
+
|  06:38
 
|Come back to our program.
 
|Come back to our program.
  
 
|-
 
|-
|  06.41
+
|  06:41
| Suppose, here at the end of if statement I will type a semicolon.
+
| Suppose, here at the end of '''if''' statement I will type a semicolon (;).
  
 
|-
 
|-
|  06.47
+
|  06:47
|Let see what will happen.Click on '''Save.'''
+
|Let us see what will happen. Click on '''Save.'''
 
+
 
+
  
 
|-
 
|-
|  06.50
+
|  06:50
 
|  Let us execute. Come back to our terminal.
 
|  Let us execute. Come back to our terminal.
  
 
|-
 
|-
|  06.53
+
|  06:53
 
|Let us compile as before.  
 
|Let us compile as before.  
  
 
|-
 
|-
|  06.56
+
|  06:56
|  We see an error: else without a previous if
+
|  We see an error: ''' 'else' without a previous 'if' '''
  
 
|-
 
|-
| 07.02
+
| 07:02
| Come back to our program.It is an syntax error.
+
| Come back to our program. It is a syntax error.
  
 
|-
 
|-
|  07.07
+
|  07:07
|If statement will never terminate with a semicolon.
+
|'''if''' statement will never terminate with a semicolon.
  
 
|-
 
|-
|  07.10
+
|  07:10
|And the else if statement will never work without an if.
+
|And the '''else if''' statement will never work without an '''if'''.
  
 
|-
 
|-
| 07.16
+
| 07:16
|  Let us fix the error. Delete the semicolon ; here
+
|  Let us fix the error. Delete the semicolon (;) here.
  
 
|-
 
|-
| 07.22
+
| 07:22
 
|  Now Click on '''Save.'''
 
|  Now Click on '''Save.'''
  
 
|-
 
|-
|  07.25
+
|  07:25
 
|  Let us execute. Come back to the terminal.
 
|  Let us execute. Come back to the terminal.
  
 
|-
 
|-
| 07.29
+
| 07:29
 
|  Let us compile as before. Let us execute as before.
 
|  Let us compile as before. Let us execute as before.
  
 
|-
 
|-
|  07.35
+
|  07:35
|Enter the value of a and b
+
|Enter the value of a and b.
  
 
|-
 
|-
|  07.37
+
|  07:37
 
|I will give the values as 3 and 6.
 
|I will give the values as 3 and 6.
  
 
|-
 
|-
|  07.44
+
|  07:43
 
|The output is displayed as  
 
|The output is displayed as  
  
 
|-
 
|-
|  07.46
+
|  07:45
|Sum of a and b is 9. Sum is less than 10.
+
|'''Sum of a and b is 9. Sum is less than 10'''.
  
 
|-
 
|-
|  07.52
+
|  07:52
| | NOW WE WILL SEE HOW TO EXECUTE THE SAME PROGRAM IN C++.  
+
| NOW WE WILL SEE HOW TO EXECUTE THE SAME PROGRAM IN C++.  
  
 
|-
 
|-
|  07.57
+
|  07:57
 
|Come back to our program.
 
|Come back to our program.
  
 
|-
 
|-
08.00
+
07:59
|   I will change a few things here.
+
| I will change a few things here.
  
 
|-
 
|-
| 08.03
+
| 08:03
|  Press '''Shift, Ctrl and S'''  keys simultaneously on your keyboard.'''
+
|  Press '''Shift, Ctrl''' and '''S'''  keys simultaneously on your keyboard.  
  
 
|-
 
|-
|  08.11
+
|  08:11
|Now save the file with an extension .'''cpp''' and''' '''click''' '''on''' Save'''
+
|Now save the file with an extension '''dot cpp''' and click on ''' Save'''.
  
 
|-
 
|-
|  08.20
+
|  08:20
|   We will change the header file as'''iostream'''
+
| We will change the header file as '''iostream'''.
  
 
|-
 
|-
| 08.26  
+
| 08:26  
 
|  Let us include the '''using '''statement here.
 
|  Let us include the '''using '''statement here.
  
 
|-
 
|-
|  08.30
+
|  08:30
|  Now click on the search for and replace text option .  
+
|  Now click on the Search for and replace text option.  
 
|-
 
|-
|  08.36
+
|  08:35
|let us replace '''printf '''statement with '''cout''' '''statement.'''
+
|Let us replace the '''printf '''statement with the '''cout''' statement.
  
 
|-
 
|-
|  08.40
+
|  08:40
|Click on '''Replace all''' and click on '''Close'''
+
|Click on '''Replace all''' and click on Close.
 
+
 
+
  
 
|-
 
|-
|  08.46
+
|  08:46
|  Now delete the   closing brackets here.
+
|  Now delete the closing brackets here.
  
 
|-
 
|-
|  08.50
+
|  08:49
|Replace the '''scanf''' statement with the '''cin''' statement.
+
|Replace the '''scanf()''' statement with the '''cin''' statement.
  
 
|-
 
|-
|  08.54
+
|  08:54
|Type '''cin and two closing angle brackets >>'''
+
|Type '''cin''' and '''two closing angle brackets >>'''.
  
 
|-
 
|-
| 09.00   
+
| 09:00   
|As we use '''cin >> function''' to read a line in C++.  
+
|As we use '''cin >>''' function to read a line in C++.  
 
+
 
   
 
   
 
|-
 
|-
| 09.06
+
| 09:05
 
| Now delete the '''format specifiers'''.
 
| Now delete the '''format specifiers'''.
  
 
|-
 
|-
|  09.09
+
|  09:09
|Delete the '''comma''' and '''ampersand''' &'''
+
|Delete the '''comma''' and '''ampersand &'''.
  
 
|-
 
|-
|  09.12
+
|  09:12
 
|Delete the comma here and type two closing angle brackets.
 
|Delete the comma here and type two closing angle brackets.
  
 
|-
 
|-
|  09.17
+
|  09:17
|Again delete the '''ampersand'''and the closing brackets. Now Click on '''Save'''.
+
|Again delete the '''ampersand'''and the closing brackets. Now click on '''Save'''.
  
 
|-
 
|-
| 09.25
+
| 09:25
 
|  Here delete the closing bracket and the comma.
 
|  Here delete the closing bracket and the comma.
  
 
|-
 
|-
|  09.32
+
|  09:31
|Now delete the ''''backslash n'''' and ''''format specifier'''
+
|Now delete the '''backslash n (\n)''' and '''format specifier'''.
'
+
 
|-
 
|-
|  09.37  
+
|  09:37  
| Now Type two opening brackets  
+
| Now type two opening brackets.
  
 
|-
 
|-
|  09.42
+
|  09:42
|Again type two opening angle brackets  and''' within the double quotes type backslash n “\n”.'''
+
|Again type two opening angle brackets  and '''within the double quotes type backslash n “\n”.'''
  
 
|-
 
|-
|  09.49
+
|  09:49
 
|Here also we will delete the closing bracket.
 
|Here also we will delete the closing bracket.
  
 
|-
 
|-
|  09.54
+
|  09:53
 
|Now again delete the closing bracket here and here.
 
|Now again delete the closing bracket here and here.
  
 
|-
 
|-
|  09.59  
+
|  09:59  
|Now   Click on '''Save'''
+
|Now click on '''Save'''.
  
 
|-
 
|-
| 10.03
+
| 10:02
 
| Let us execute.
 
| Let us execute.
  
 
|-
 
|-
|  10.04
+
|  10:04
|| Come back to the terminal.let me clear the prompt.
+
|| Come back to the terminal. Let me clear the prompt.
  
 
|-
 
|-
|  10.10
+
|  10:10
|To compile   type '''g++ space ifstmt.cpp space -o space if1'''
+
|To compile, type '''g++ space ifstmt.cpp space -o space if1'''
  
 
|-
 
|-
|  10.21
+
|  10:20
|Here we have '''if1''' because we don't want to overwrite the output parameter '''if '''for the file ifstmt.c
+
|Here we have 'if1' because we don't want to overwrite the output parameter '''if '''for the file 'ifstmt.c'.
  
 
|-
 
|-
|  10.31
+
|  10:31
|Now Press '''Enter'''
+
|Now Press 'Enter'.To execute type '''./if1''' (dot slash if1) and press '''Enter'''.
  
 
|-
 
|-
|  10.33
+
|  10:39
|To execute type ./if1 and Press '''Enter'''
+
|Enter the value of '''a''' and '''b'''. I will give the values as 20 and 10.
  
 
|-
 
|-
|  10.39
+
|  10:48
|Enter the value of''' a''' and '''b'''. I will give the values as 20 and 10.
+
|The output is displayed as '''Sum of a and b is 30'''
  
 
|-
 
|-
|  10.48
+
|  10:52
|The output is displayed as,  Sum of a and b is '''30'''.
+
|'''Sum is greater than 20'''
  
 
|-
 
|-
|  10.53
+
|  10:56
|Sum is greater than 20.
+
 
+
|-
+
|  10.56
+
 
|This brings us to the end of this tutorial.
 
|This brings us to the end of this tutorial.
  
 
|-
 
|-
|  10.59
+
|  10:59
 
|  Now come back to our slides.
 
|  Now come back to our slides.
 +
 
|-
 
|-
| 11.03
+
| 11:02
 
|  Let us summarize.
 
|  Let us summarize.
  
 
|-
 
|-
|  11.04
+
|  11:04
|In this tutorial we learned, if statement eg. if(condition)
+
|In this tutorial we learned 'if' statement eg. if(condition),
 
+
{…........
+
 
+
}
+
 
+
|-
+
|  11.12
+
| And else if statement eg. else if(condition)
+
 
+
{….........
+
 
+
}
+
  
 
|-
 
|-
|  11.18
+
|  11:11
| As an assignment,
+
| And 'else if' statement eg. else if(condition).
  
 
|-
 
|-
|  11.19
+
|  11:17
|Write a program to check '''a''' is greater than '''b''' or less than '''b.'''
+
| As an assignment, Write a program to check 'a' is greater than 'b' or less than 'b'.
  
 
|-
 
|-
|  11.24
+
|  11:24
|'''Hint: ''' use if statement.
+
|Hint: use 'if' statement.
  
 
|-
 
|-
|  11.28
+
|  11:28
|Write another program to check which value is greater '''a,''' '''b''' or '''c.'''
+
|Write another program to check which value is greater 'a', 'b' or 'c'.  
  
 
|-
 
|-
|  11.34
+
|  11:34
|'''Hint:''' use else-if statement.
+
|Hint: use 'else-if' statement.
  
 
|-
 
|-
|  11.39
+
|  11:38
|  Watch the video available at the link shown below. http://spoken-tutorial.org /What\_is\_a\_Spoken\_Tutorial
+
|  Watch the video available at the link shown below.  
  
 
|-  
 
|-  
|  11.41
+
|  11:41
 
|It summarizes the Spoken Tutorial project.  
 
|It summarizes the Spoken Tutorial project.  
  
 
|-
 
|-
|  11.44
+
|  11:44
 
|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.
  
 
|-
 
|-
|11.49
+
|11:48
 
|| The Spoken Tutorial Project Team,
 
|| The Spoken Tutorial Project Team,
  
 
|-
 
|-
|  11.51
+
|  11:50
 
|Conducts workshops using spoken tutorials.  
 
|Conducts workshops using spoken tutorials.  
  
 
|-
 
|-
|  11.54
+
|  11:54
 
|Gives certificates to those who pass an online test.  
 
|Gives certificates to those who pass an online test.  
  
 
|-
 
|-
|  11.58
+
|  11:57
|For more details, please write to,   contact [at] spoken hyphen tutorial dot org.
+
|For more details, please write to, contact @ spoken hyphen tutorial dot org.
  
 
|-
 
|-
|  12.05
+
|  12:04
 
|  Spoken Tutorial Project is a part of the Talk to a Teacher project.
 
|  Spoken Tutorial Project is a part of the Talk to a Teacher project.
  
 
|-
 
|-
|  12.09
+
|  12:09
 
|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.
  
 
|-
 
|-
|  12.16
+
|  12:15
|More information on this Mission is available at the link shown below.  (http://spoken-tutorial.org\NMEICT-Intro)
+
|More information on this Mission is available at the link shown below.   
  
 
|-
 
|-
| 12.21
+
| 12:20
| This is Ashwini Patil from IIT Bombay
+
| This is Ashwini Patil from IIT Bombay.
  
 
Thank You for watching.
 
Thank You for watching.
 
|}
 
|}

Latest revision as of 11:17, 5 September 2017

Time Narration
00:02 Welcome to the spoken tutorial on Conditional statements in C and C++.
00:08 In this tutorial we will learn:
00:11 How to execute a single statement
00:14 How to execute group of statements.
00:16 We will do this through examples.
00:19 We will also see some common errors and their solutions.
00:25 To record this tutorial, I am using Ubuntu Operating system version 11.10.
00:31 gcc and g++ Compiler version 4.6.1.
00:38 Let us start with the introduction to conditional statements.
00:43 A statement in a program controls the flow of program execution.
00:49 It helps to make decision on what code is to be executed.
00:55 We can check the conditions, whether true or false.
01:00 We can execute a single statement or a group of statements.
01:07 Let us understand the flow of if statements.
01:13 Here, if the condition is true then statement 1 will be executed.
01:20 If the condition is false then statement 2 will be executed.
01:29 Now we will see the flow of else if statement.
01:32 Here, if condition 1 is true then statement 1 will be executed.
01:41 If condition 1 is false then it will check for another condition that is condition 2.
01:49 If condition 2 is true then statement 3 will be executed.
01:54 And If condition 2 is false then statement 2 will be executed.
02:02 Now Let us move on to our program.
02:06 I have already typed the code on the editor.
02:09 So, let me open it.
02:13 Note that our file name is ifstmt.c.
02:18 In this program we will calculate the sum of two numbers and will check a few conditions.
02:26 Let me explain the code now.
02:30 This is our header file.
02:34 This is our main() function.
02:38 Here we have declared three integer variables a, b and sum.
02:46 Here we are asking for user input.
02:49 User will enter the values of a and b.
02:52 The values will be stored in variable a and variable b.
02:58 The scanf() function reads data from the console.
03:02 It then stores the result in the given variable.
03:06 The format specifier in the scanf() helps to know the type of data.
03:10 Like here we have %d, it denotes that we are dealing with integer data type.
03:18 Here we add the values of a and b.
03:22 We will store the result in sum.
03:25 Then we print the result.
03:29 This is our if statement.
03:30 Here, we check the condition whether sum is greater than 20.
03:36 If the condition is true, then we print Sum is greater than 20.
03:42 Now let me comment out these lines.
03:48 This is our return statement.
03:51 Now click on Save.
03:53 First we will see the execution of if statement.
03:58 Please open the terminal window by pressing Ctrl, Alt and T keys simultaneously on your keyboard.
04:09 To compile, type gcc space ifstmt dot c space -o space if and press Enter.
04:20 To execute, type ./if (dot slash if). Press Enter.
04:26 It is displayed as Enter the values of a and b.
04:31 I will give the values as 10 and 12.
04:38 The output is displayed as Sum of a and b is 22. Sum is greater than 20.
04:45 Now come back to our program.
04:48 We will check another condition.
04:52 Let me remove the comment from here.
04:56 I will give the comment here.
05:00 Now click on Save. This is our else-if statement.
05:05 Here, we check another condition whether Sum is greater than 10.
05:11 If the condition is true then we print 'Sum is greater than 10 and less than 20'.
05:18 Now come back to our terminal.
05:20 Let us compile as before.
05:23 Let us execute as before.
05:26 It is displayed as
05:28 Enter the value of a and b.
05:30 I will give the values as 10 and 2.
05:35 The output is displayed as: Sum of a and b is 12.
05:38 Sum is greater than 10 and less than 20.
05:42 Let me clear the prompt.
05:44 Now come back to our program.
05:48 I will remove the comment from here and here. Now click on Save.
05:56 If both the above conditions are false then we print 'Sum is less than 10'.
06:04 This is our else statement.
06:07 Now let us execute and see. Come back to our terminal.
06:11 Let us compile as before. Let us execute as before.
06:18 Here it is displayed as Enter the value of a and b.
06:22 I will give the values as 3 and 5.
06:27 The output is displayed as sum of a and b is 8.
06:31 Sum is less than 10.
06:34 Now we will see some common errors which we can come across.
06:38 Come back to our program.
06:41 Suppose, here at the end of if statement I will type a semicolon (;).
06:47 Let us see what will happen. Click on Save.
06:50 Let us execute. Come back to our terminal.
06:53 Let us compile as before.
06:56 We see an error: 'else' without a previous 'if'
07:02 Come back to our program. It is a syntax error.
07:07 if statement will never terminate with a semicolon.
07:10 And the else if statement will never work without an if.
07:16 Let us fix the error. Delete the semicolon (;) here.
07:22 Now Click on Save.
07:25 Let us execute. Come back to the terminal.
07:29 Let us compile as before. Let us execute as before.
07:35 Enter the value of a and b.
07:37 I will give the values as 3 and 6.
07:43 The output is displayed as
07:45 Sum of a and b is 9. Sum is less than 10.
07:52 NOW WE WILL SEE HOW TO EXECUTE THE SAME PROGRAM IN C++.
07:57 Come back to our program.
07:59 I will change a few things here.
08:03 Press Shift, Ctrl and S keys simultaneously on your keyboard.
08:11 Now save the file with an extension dot cpp and click on Save.
08:20 We will change the header file as iostream.
08:26 Let us include the using statement here.
08:30 Now click on the Search for and replace text option.
08:35 Let us replace the printf statement with the cout statement.
08:40 Click on Replace all and click on Close.
08:46 Now delete the closing brackets here.
08:49 Replace the scanf() statement with the cin statement.
08:54 Type cin and two closing angle brackets >>.
09:00 As we use cin >> function to read a line in C++.
09:05 Now delete the format specifiers.
09:09 Delete the comma and ampersand &.
09:12 Delete the comma here and type two closing angle brackets.
09:17 Again delete the ampersandand the closing brackets. Now click on Save.
09:25 Here delete the closing bracket and the comma.
09:31 Now delete the backslash n (\n) and format specifier.
09:37 Now type two opening brackets.
09:42 Again type two opening angle brackets and within the double quotes type backslash n “\n”.
09:49 Here also we will delete the closing bracket.
09:53 Now again delete the closing bracket here and here.
09:59 Now click on Save.
10:02 Let us execute.
10:04 Come back to the terminal. Let me clear the prompt.
10:10 To compile, type g++ space ifstmt.cpp space -o space if1
10:20 Here we have 'if1' because we don't want to overwrite the output parameter if for the file 'ifstmt.c'.
10:31 Now Press 'Enter'.To execute type ./if1 (dot slash if1) and press Enter.
10:39 Enter the value of a and b. I will give the values as 20 and 10.
10:48 The output is displayed as Sum of a and b is 30
10:52 Sum is greater than 20
10:56 This brings us to the end of this tutorial.
10:59 Now come back to our slides.
11:02 Let us summarize.
11:04 In this tutorial we learned 'if' statement eg. if(condition),
11:11 And 'else if' statement eg. else if(condition).
11:17 As an assignment, Write a program to check 'a' is greater than 'b' or less than 'b'.
11:24 Hint: use 'if' statement.
11:28 Write another program to check which value is greater 'a', 'b' or 'c'.
11:34 Hint: use 'else-if' statement.
11:38 Watch the video available at the link shown below.
11:41 It summarizes the Spoken Tutorial project.
11:44 If you do not have good bandwidth, you can download and watch it.
11:48 The Spoken Tutorial Project Team,
11:50 Conducts workshops using spoken tutorials.
11:54 Gives certificates to those who pass an online test.
11:57 For more details, please write to, contact @ spoken hyphen tutorial dot org.
12:04 Spoken Tutorial Project is a part of the Talk to a Teacher project.
12:09 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
12:15 More information on this Mission is available at the link shown below.
12:20 This is Ashwini Patil from IIT Bombay.

Thank You for watching.