Difference between revisions of "Java/C2/Relational-Operations/English-timed"
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| − | | For this tutorial, we are using: | + | | For this tutorial, we are using: |
| − | '''Ubuntu 11.10''', | + | |
| + | '''Ubuntu 11.10''', | ||
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'''Eclipse 3.7''' | '''Eclipse 3.7''' | ||
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| − | | watch the video available at[http://spoken-tutorial.org/What_is_a_Spoken_Tutorial]. | + | | watch the video available at [http://spoken-tutorial.org/What_is_a_Spoken_Tutorial]. |
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| 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. | ||
Revision as of 12:38, 3 April 2015
| Time | Narration |
| 00:01 | Welcome to the spoken tutorial on Relational Operators in Java. |
| 00:07 | In this tutorial, we will learn about the |
| 00:09 | boolean data type, |
| 00:10 | Relational operators and |
| 00:12 | how to compare data using Relational operators. |
| 00:17 | For this tutorial, we are using:
Ubuntu 11.10, JDK 1.6 and Eclipse 3.7 |
| 00:26 | To follow this tutorial, you must have knowledge of data types in Java. |
| 00:31 | If not, for relevant tutorials, please visit our website as shown. |
| 00:39 | Relational operators are used to check for conditions. |
| 00:43 | Their output is a variable of boolean data type. |
| 00:48 | A boolean data type is of size 1 bit. |
| 00:51 | It stores only two values. |
| 00:54 | true or false. |
| 00:56 | true is the output when the condition is true. |
| 00:59 | false is the output if the condition is not true. |
| 01:06 | Here is a list of the relational operators available. |
| 01:10 | * greater than |
| 01:12 | * less than |
| 01:13 | * equal to |
| 00:14 | * greater than or equal to |
| 01:15 | * less than or equal to |
| 01:17 | * not equal to |
| 01:19 | We shall look into each of them in detail. |
| 01:22 | Switch to Eclipse. |
| 01:27 | Here we have the Eclipse IDE and the skeleton required for the rest of the code. |
| 01:33 | I have created a class BooleanDemo and added the Main method. |
| 01:38 | Now let us add some expressions. |
| 01:41 | Type boolean b ; |
| 01:47 | The keyword boolean declares the data type of the variable b as boolean. |
| 01:53 | We shall store the result of our condition in b. |
| 01:58 | We shall define a variable weight and check for a condition using that variable. |
| 02:05 | int weight equal to 45; |
| 02:13 | We shall check if the value in weight is greater than 40. |
| 02:18 | b equal to weight greater than 40; |
| 02:28 | This statement says: check if the value of variable is greater than 40 and store the result in 'b'. |
| 02:37 | Now, let us print the value of 'b'. |
| 02:41 | System dot out dot println(b); |
| 02:49 | Save and Run. |
| 02:59 | As we can see, the output is True. |
| 03:02 | Let us see what happens if the value is less than 40. |
| 03:07 | Change weight to 30. |
| 03:12 | Save and run. |
| 03:20 | We can see that the output is False as expected. |
| 03:24 | This way, the greater than symbol is used to check if one value is greater than the other. |
| 03:30 | Similarly, less than symbol is used to check if one value is less than the other. |
| 03:37 | Let us change the greater than to less than symbol. |
| 03:43 | So, We are checking if the value of weight is less than 40. |
| 03:48 | Save, Run. |
| 03:56 | As we can see, the output is true as expected. |
| 04:01 | Let us change the value of weight to 45 and see the output. |
| 04:09 | Save and Run. |
| 04:16 | We see that we get a false because the condition |
| 04:21 | weight less than 40 is not true. |
| 04:25 | Now let us see how to check if a value is equal to another. |
| 04:31 | To do that, we use two equal to symbols. |
| 04:35 | Change less than symbol to double equal to. |
| 04:41 | Save and Run. |
| 04:48 | As we can see, the output is false because the value of weight is not equal to 40. |
| 04:55 | Now let us change the weight to 40 and see the output. |
| 05:01 | Save and Run. |
| 05:08 | As we can see, the output is True. |
| 05:12 | This way, double equal to is used for checking equality. |
| 05:16 | Please be careful because, often people use a single equal to symbol for checking equality. |
| 05:22 | And this gives unnecessary errors. |
| 05:26 | Next we'll see how to check for less than or equal to. |
| 05:30 | To do that, we will use a less than symbol followed by an equal to symbol. |
| 05:35 | Change the double equal to, to less than equal to. |
| 05:42 | Save and Run. |
| 05:50 | The output is True as expected. |
| 05:53 | Now let us change the value of weight to see if the less than check is performed. |
| 05:59 | Change 40 to 30. |
| 06:04 | Save and Run. |
| 06:14 | We see, that although the weight is not equal to 40 we get the output as True because it is less than 40. |
| 06:22 | Let us see what happens if the value of weight is greater than 40. |
| 06:27 | Let's say 50. Save and Run. |
| 06:39 | As we can see, the output is False because the value of weight is not equal to 40. |
| 06:44 | And it also not less than 40. |
| 06:48 | Similarly, we use a greater than symbol followed by an equal to symbol for checking greater than or equal to. |
| 06:55 | Let us try it. |
| 06:57 | Change less than equal to to greater than equal to. |
| 07:04 | Save and Run. |
| 07:10 | As we can see, the output is true because weight is greater than 40. |
| 07:16 | Let us change weight to a value less than 40. Let's say 30. |
| 07:25 | Save and Run. |
| 07:32 | We get a false because the value of weight is not greater than 40 and also not equal to 40. |
| 07:39 | Next, we’ll see how to check for not equal to. |
| 07:46 | It is done by using an exclamation mark followed by an equal to symbol. |
| 07:53 | Change greater than to exclamation. |
| 07:59 | So, this statement says: check if the value of weight is not equal to 40 and store the result in b. |
| 08:08 | Save and Run. |
| 08:16 | As we can see, the output is true because the values of weight is not equal to 40. |
| 08:23 | Let us change the weight to 40 and see the output. |
| 08:28 | Change 30 to 40. |
| 08:31 | Save, Run. |
| 08:38 | We get a false because the condition weight not equal to 40 is false. |
| 08:45 | The not equal to condition can be thought of as opposite of equal to condition. |
| 08:50 | This is how we use the various relational operators to compare data in Java. |
| 08:58 | This brings us to the end of this tutorial. |
| 09:01 | In this tutorial we have learnt about: the boolean data type, |
| 09:06 | the relational operators and |
| 09:08 | how to use relational operators to compare data. |
| 09:13 | As an assignment for this tutorial, find out if the two expressions shown are equivalent. |
| 09:23 | To know more about the Spoken Tutorial project, |
| 09:23 | watch the video available at [1]. |
| 09:28 | It summarizes the Spoken Tutorial project. |
| 09:31 | If you do not have good bandwidth, you can download and watch it. |
| 09:36 | The Spoken Tutorial Project Team: |
| 09:38 | Conducts workshops using 'Spoken Tutorials'. |
| 09:40 | Gives certificates for those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org. |
| 09:50 | Spoken Tutorial Project is a part of the 'Talk to a Teacher' project. |
| 09:54 | It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
| 10:00 | More information on this mission is available at spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro. |
| 10:05 | This tutorial has been contributed by TalentSprint. Thanks for joining. |
