Java/C2/Relational-Operations/English-timed

From Script | Spoken-Tutorial
Revision as of 12:14, 12 June 2013 by Sneha (Talk | contribs)

Jump to: navigation, search
Time' Narration
00:02 Welcome to the spoken tutorial on Relational Operators in C and C++.
00:07 In this tutorial, we will learn about:
00;09 Relational operators like
00:12 Less than: eg. a < b
00:15 Greater than: eg. a > b
00:18 Less than or equal to: eg. a <= b
00:23 Greater than or equal to: eg. a >= b
00:28 Equal to: eg. a == b
00:31 Not equal to: eg. a != b
00:38 To record this tutorial, I am using: Ubuntu 11.10 as the operating system
00:43 gcc and g++ Compiler version 4.6.1 in Ubuntu.
00:50 Let us begin with an introduction.
00:53 Relational operators are used to compare integer and floating point numbers.
00:58 Expressions using relational operators return 0 for false and 1 for true.

Return values:

0 when False

1 when True

01:04 Now I will demonstrate the relational operators with the help of a C program.
01:10 I have already made the program.
01:11 So, I'll open the editor and explain the code.
01:16 First, we declare two variables a and b.
01:21 This printf statement prompts the user to enter the values of a and b.
01:27 This scanf statement takes input for the variables a and b.
01:33 Now we have the greater than operator.
01:35 This operator compares the two operands on either side of the operator.
01:39 It returns' False if a is greater than b.
01:44 This printf statement is executed if the above condition is true.
01:48 If the above condition is false then it is skipped.
01:51 To control then jumps to the next statement.
01:54 We now have the less than operator.
01:56 This too compares the operands.
01:58 It returns true when a is less than b.
02:03 This printf statement is executed if the above condition is true.
02:07 It is skipped otherwise.
02:09 Let's execute the code till here.
02:13 First comment out the following. Type /* */
02:24 Click on Save.
02:26 I have saved my file as relational.c
02:30 Open the terminal window by pressing Ctrl, Alt and T keys simultaneously.
02:36 To compile, type the following on the terminal gcc relational.c -o rel
02:50 Press Enter.
02:52 To execute type ./rel Press Enter.


02:58 I enter a as 8 and b as 3.
03:02 The output is displayed:
03:04 8 is greater than 3.
03:07 You can try executing this code with different values of a and b.
03:12 Coming back to the code.
03:14 Delete the comment from here and put it here.


03:24 Now we have the less than or equal to operator.
03:29 This operator compares the two operands on either side of the operator.
03:33 It returns true if a is less than or equal to b.
03:39 This printf statement is executed if the above condition is true.
03:43 If the above condition is false then it is skipped.
03:46 The control then jumps to the next statement.
03:50 Next comes the greater than or equal to operator.
03:53 It compares a and b and returns true if a is greater than or equal to b.
04:01 If the condition is true then this printf statement will be executed.
04:05 Now let's execute the code till here.
04:08 Click on Save.
04:10 Switch back to the terminal.
04:12 Compile and execute as before.


04:17 I enter a as 8 and b as 3.
04:23 The output is displayed:
04:25 8 is greater than or equal to 3
04:30 Now Coming back to rest of the code.
04:33 Delete the multiline comments from here ands here.
04:43 we now have the equal to operator.
04:47 It is denoted by double equal (==) signs.
04:50 This operator returns true when both operands are equal to one another.
04:57 This printf statement executes when a is equal to b.
05:01 If not, the control then jumps on to the next statement.
05:06 Similarly, we have the not equal to operator.
05:09 This operator returns true when the operands are not equal to one another.
05:15 This printf statment will execute when a is not equal to b.
05:21 Coming to the end of the program.

Return 0;

05:24 Click on Save.
05:26 Switch back to the terminal.
05:28 Compile and execute as before.


05:33 Enter a as 8 and b as 3.
05:39 The output is displayed on the screen:
05:41 8 is not equal to 3
05:45 So, we see how the relational operaotors work.
05:48 Try executing this code with different set of inputs.
05:52 \Now, writing a smilar program in C++ is quite easy.
05:56 There are a few differences in the syntax.
06:00 I have already made the code in C++.
06:04 Their is the code for relational operators in C++.
06:09 Notice that the header is different.
06:12 Also we have the using statement here.
06:16 The output statement in C++ is cout.
06:19 And the input statement in C++ is cin.
06:22 So, apart from these differences, the two codes are very similar.
06:27 Click on save.
06:29 Please make sure the file is saved with the extension .cpp
06:33 I have saved my file as relational.cpp
06:38 Let's compile the code.
06:40 Open the terminal and type g++ relational.cpp -o rel1
06:51 To execute Type './ rel1, Press Enter.


06:57 I enter a as 8 and b as 3.
07:01 The output is displayed:
07:03 We see that the output is same as the one in C code.
07:08 Now let us see an error which we can come across.
07:11 Come back to the program
07:13 Suppose here we replace the double equal to sign with the single equal to.
07:20 Click on Save.
07:21 Come back to the terminal.
07:24 Compile and execute as before.
07:34 Here we see it is showing 3 is equal to 3.
07.38 Come back to our program
07:40 This is because here we have an assignment operator.
07:44 So value of b is assigned to a.
07:47 Now Let us fix this error.
07:49 Type an equal to sign.
07:52 Click on Save
07:55 Switch back to the terminal
07:56 compile and execute as before.
08:04 The output is now correct.
08:06 Let's summarize the tutorial.
08:09 In this tutorial, we learnt
08:10 Relational operators like
08:12 Less than: eg. a b
08:18 Less than or equal to: eg. a<=b
08:23 Greater than or equal to: eg. a>=b
08:27 Equal to: eg. a==b
08:30 Not equal to: eg. a!=b
08:34 As an assignment
08:35 Write a program that takes the marks of three students as input.
08:40 Compare the marks to see which student has scored the highest.
08:44 Check also if two or more students have scored equal marks.
08:49 Watch the video available at the following link
08:51 It summarises the Spoken Tutorial project
08:54 If you do not have good bandwidth, you can download and watch it


08:58 The Spoken Tutorial Project Team
09:00 Conducts workshops using spoken tutorials
09:03 Gives certificates for those who pass an online test
09:06 For more details, please write to contact at spoken hyphen tutorial dot org


09:14 Spoken Tutorial Project is a part of the Talk to a Teacher project
09:18 It is supported by the National Mission on Education through ICT, MHRD, Government of India
09:24 More information on this Mission is available at
09:27 spoken hyphen tutorial dot org slash NMEICT hyphen Intro


09:35 This is Ritwik Joshi from IIT Bombay.

Thank you for joining.

Contributors and Content Editors

Gaurav, PoojaMoolya, Ranjana, Sandhya.np14, Sneha