Java/C2/Relational-Operations/English-timed
From Script | Spoken-Tutorial
| 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. |
