Java/C2/Numerical-Datatypes/English-timed

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Time Narration
00:01 Welcome to the spoken tutorial on Numerical Datatypes in Java.
00:07 In this tutorial, we will learn about:
00:10 The various Numerical Datatypes available in Java and
00:13 How to use them to store numerical data.


00:18 For this tutorial we are using
  • Ubuntu 11.10,
  • JDK 1.6 and
  • Eclipse 3.7.0


00:27 To follow this tutorial, you must know how to write and run a simple java program in Eclipse.


00:34 If not, for relevant tutorial please visit our website as shown



00:42 The data type used to store integers is called int


00:47 The data type used to store decimal numbers is called float.


00:52 Let us define and use integers first.
01:02 Here, we have the Eclipse IDE and the skeleton required for the rest of the code.
01:10 We have created a class NumericalData and added the main method to it.


01:15 Now let us see how to store a number.
01:20 int distance equal to 28


01:27 This statement stores the integer value in the name distance.
01:33 The name distance is called an integer variable.


01:37 Now we shall use the variable distance to print the value stored in it.
01:47 System dot out dot println. In parentheses distance.


02:01 This statement prints the value of the variable distance
02:06 Save the file and Run it
02:14 We can see that the value 28 has been stored in distance and it has been printed.


02:21 Now let us change the value stored in the variable.
02:25 change 28 to 24



02:29 Save and Run
02:34 We see that the output has changed accordingly.
02:39 int can also store negative values.


02:42 Change 24 to minus 25



02:48 Save and Run '.
02:56 As we can see, even negative values can be stored in variables of the type int.
03:02 The Data type int is enough for most of our programming needs.


03:06 But it can only store values up to a limit.


03:10 Let us try to store a large value and see what happens.
03:25 As we can see, there is a red line below the number which indicates an error.
03:34 The error message says,the number is out of range for a variable of the type int


03:42 int takes 32 bits of memory and can store values only from -2 power 31 to 2 power 31.
03:49 To store large numbers, Java provides the long data type.


03:54 Let us use it to store a large value.
03:59 Change int to long and
04:04 add a capital L at the end of the number.


04:11 Save it with Ctrl, S


04:16 We see that now there is no error.


04:19 Let us run it with Ctrl, F11. The value has been printed


04:27 We can see that large numbers can be stored in a long variable.
04:32 Now let us store a decimal number in a int variable.


04:37 Change long to int and change the number to 23.5;
04:50 As we can see, there is an error. That is because int can only store integers.


05:00 To store decimal numbers, we have to use float.
05:05 change the data type to float.


05:10 And add an f at the end of the value.
05:17 save it.


05:19 We see that now their is no error.


05:22 run it with Control F11
05:29 As we can see, the decimal value has been stored and the value has been printed.
05:37 Now let us change the value of the variable distance


05:46 Add a lot of numbers after the decimal point as shown.
05:53 Save it and Run it


06:01 we see, that the output is little different from what has been stored.


06:06 This happens because there is a limit to the precision of a floating point number.


06:11 It is rounded off to the closest possible number if it cannot be stored accurately.
06:18 Now let us see the naming rules for variables.


06:23 Add a number 2 before the name.


06:30 we see that, there is a syntax error.


06:34 This is because a variable name must only start with an alphabet or an underscore.


06:40 But generally underscore is not used to start a variable name.
06:45 Now let us add the number at the end of the variable name.


06:55 We see that, there is no error.


06:59 A variable name can have digits but not at the beginning.
07:04 Now add an 'underscore' in the middle of the name
07:15 we see that there is no error.


07:17 Which means an underscore is permitted in a variable name.


07:22 But any other punctuation in a variable name that give an syntax error or other errors.


07:28 This is how you store numerical data in Java.
07:35 This brings us to the end of the tutorial.
07:38 In this tutorial we have learnt about the various numerical datatypes.
07:44 And How tostore numerical data.
07:46 And We have also learnt the rules for naming a variable.
07:51 As an assignment for this tutorial,


07:53 Read about other numerical data types and
07:56 see how they are different from int and float.


08:00 Java tutorials are available at the following link.
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08:11 It summarises the Spoken Tutorial project
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08:39 It supported by the National Mission on Education through ICT, MHRD, Government of India.


08:45 More information on this Mission is available at the following link.
08:51 This tutorial has been contributed by TalentSprint. Thanks for joining.



Contributors and Content Editors

Gaurav, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha