Difference between revisions of "Java/C2/Relational-Operations/English-timed"

From Script | Spoken-Tutorial
Jump to: navigation, search
Line 138: Line 138:
  
 
|-
 
|-
|  01:5
+
|  01:58
 
|  We shall define a variable weight and check for a condition using that variable.
 
|  We shall define a variable weight and check for a condition using that variable.
  

Revision as of 15:01, 23 June 2014

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 the 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 thegreater 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.
06:274 Let 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. Lets 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 30to 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 two values
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 summarises 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.



Contributors and Content Editors

Gaurav, PoojaMoolya, Ranjana, Sandhya.np14, Sneha