C-and-C++/C2/Relational-Operators/English-timed

Time	Narration
00.01	Welcome to the spoken tutorial on Relational Operators in C and C++.
00.06	In this tutorial, we will learn about:
00.09	Relational operators like
00.11	Less than: eg. a < b
00.14	Greater than: eg. a > b
00.17	Less than or equal to: eg. a <= b
00.22	Greater than or equal to: eg. a >= b
00.27	Equal to: eg. a == b
00.30	Not equal to: eg. a != b
00.37	To record this tutorial, I am using: Ubuntu 11.10 as the operating system
00.42	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.
00.57	Expressions using relational operators return 0 for false and 1 for true.
01.04	Now I will demonstrate the relational operators with the help of a C program.
01.09	I have already made the program.
01.11	So, I'll open the editor and explain the code.
01.15	First, we declare two variables a and b.
01.20	This printf statement prompts the user to enter the values of a and b.
01.26	This scanf statement takes input for the variables a and b.
01.32	Now we have the greater than operator.
01.35	This operator compares the two operands on either side of the operator.
01.38	It returns' True if a is greater than b.
01.43	This printf statement is executed if the above condition is true.
01.47	If the above condition is false then it is skipped.
01.50	The control then jumps to the next statement.
01.53	We now have the less than operator.
01.56	This too compares the operands.
01.57	It returns true when a is less than b.
02.02	This printf statement is executed if the above condition is true.
02.06	It is skipped otherwise.
02.09	Let's execute the code till here.
02.13	First comment out the following.
02.16	Type /*
02.21	*/
02.24	Click on Save.
02.26	I have saved my file as relational.c
02.29	Open the terminal window by pressing Ctrl, Alt and T keys simultaneously.
02.35	To compile, type the following on the terminal gcc space relational dot c space -o space rel
02.49	Press Enter.
02.51	To execute type ./rel Press Enter.
02.56	I enter a as 8 and b as 3.
03.01	The output is displayed:
03.03	8 is greater than 3.
03.07	You can try executing this code with different values of a and b.
03.11	Coming back to the code.
03.14	Delete the comment from here
03.18	and put it here.
03.24	Now we have the less than or equal to operator.
03.28	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.
03.38	This printf statement is executed if the above condition is true.
03.42	If the above condition is false then it is skipped.
03.45	The control then jumps to the next statement.
03.49	Next comes the greater than or equal to operator.
03.52	It compares a and b and returns true if a is greater than or equal to b.
04.00	If the condition is true then this printf statement will be executed.
04.05	Now let's execute the code till here.
04.07	Click on Save.
04.09	Switch back to the terminal.
04.12	Compile and execute as before.
04.17	I enter a as 8 and b as 3.
04.22	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
04.39	and 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.
05.00	If not, the control then jumps on to the next statement.
05.06	Similarly, we have the not equal to operator.
05.08	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.
05.20	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.
05.32	Enter a as 8 and b as 3.
05.38	The output is displayed on the screen:
05.40	8 is not equal to 3
05.44	So, we see how the relational operaotors work.
05.48	Try executing this code with different set of inputs.
05.51	Now, writing a similar program in C++ is quite easy.
05.56	There are a few differences in the syntax.
05.59	I have already made the code in C++.
06.04	Here is the code for relational operators in C++.
06.08	Notice that the header is different.
06.12	Also we have the using statement here.
06.15	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.
06.26	Click on save.
06.28	Please make sure the file is saved with the extension .cpp
06.32	I have saved my file as relational.cpp
06.37	Let's compile the code.
06.39	Open the terminal and type g++ relational.cpp space minus o space rel1
06.50	To execute Type './ rel1, Press Enter.
06.56	I enter a as 8 and b as 3.
07.00	The output is displayed:
07.02	We see that the output is same as the one in C program.
07.07	Now let us see an error which we can come across.
07.10	Come back to the program
07.13	Suppose here we replace the double equal to sign with the single equal to.
07.19	Click on Save.
07.21	Come back to the terminal.
07.23	Compile and execute as before.
07.33	Here we see it is showing 3 is equal to 3.
07.37	Come back to our program
07.40	This is because here we have an assignment operator.
07.43	So value of b is assigned to a.
07.46	Now Let us fix this error.
07.49	Type an equal to sign.
07.51	Click on Save
07.54	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.
08.08	In this tutorial, we learnt
08.10	Relational operators like
08.12	Less than: eg. a < b
08.14	Greater than: eg. a>b
08.17	Less than or equal to: eg. a<=b
08.22	Greater than or equal to: eg. a>=b
08.27	Equal to: eg. a==b
08.29	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.
08.39	Compare the marks to see which student has scored the highest.
08.43	Check also if two or more students have scored equal marks.
08.48	Watch the video available at the following link
08.51	It summarizes 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
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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
09.34	This is Ritwik Joshi from IIT Bombay. Thank you for joining.

Contributors and Content Editors

Ashwini, PoojaMoolya, Pratik kamble, Priyacst, Sakinashaikh, Sandhya.np14