Difference between revisions of "C-and-C++/C2/Relational-Operators/English-timed"
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Revision as of 14:51, 5 February 2014
| 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 |
| 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 |
| 09.34 | This is Ritwik Joshi from IIT Bombay.
Thank you for joining. |
Contributors and Content Editors
Ashwini, PoojaMoolya, Pratik kamble, Priyacst, Sakinashaikh, Sandhya.np14
