Difference between revisions of "Java/C2/Numerical-Datatypes/English-timed"
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{| border=1 | {| border=1 | ||
− | || ''Time''' | + | || '''Time''' |
|| '''Narration''' | || '''Narration''' | ||
|- | |- | ||
| 00:01 | | 00:01 | ||
− | | Welcome to the spoken tutorial on '''Numerical | + | | Welcome to the spoken tutorial on '''Numerical Data types''' in '''Java'''. |
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| 00:10 | | 00:10 | ||
− | |The various '''Numerical | + | | The various '''Numerical Data types ''' available in Java and |
|- | |- | ||
| 00:13 | | 00:13 | ||
− | | | + | |How to use them to '''store''' '''numerical data.''' |
− | + | ||
− | + | ||
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| 00:18 | | 00:18 | ||
− | | For this tutorial we are using | + | | For this tutorial, we are using '''Ubuntu 11.10''', '''JDK 1.6''' and '''Eclipse 3.7'''. |
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− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
|- | |- | ||
| 00:27 | | 00:27 | ||
− | | To follow this tutorial, you must | + | | To follow this tutorial, you must know how to write and '''run''' a simple java program in '''Eclipse'''. |
− | + | ||
|- | |- | ||
| 00:34 | | 00:34 | ||
− | | If not, for relevant | + | | If not, for relevant tutorials, please visit our website as shown. |
− | + | ||
− | + | ||
− | + | ||
|- | |- | ||
| 00:42 | | 00:42 | ||
− | | The data type used to store integers is called '''int''' | + | | The data type used to store integers is called '''int'''. |
− | + | ||
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| 00:47 | | 00:47 | ||
| The data type used to store decimal numbers is called '''float.''' | | The data type used to store decimal numbers is called '''float.''' | ||
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|- | |- | ||
| 00:52 | | 00:52 | ||
− | | Let us define and use integers first. | + | | Let us define and use '''integers''' first. |
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| 01:02 | | 01:02 | ||
− | | Here, we have the Eclipse IDE and the skeleton required for the rest of the code. | + | | Here, we have the 'Eclipse IDE' and the skeleton required for the rest of the code. |
|- | |- | ||
| 01:10 | | 01:10 | ||
− | | We have created a class '''NumericalData''' and added the main method to it. | + | | We have created a '''class''' '''NumericalData''' and added the '''main method''' to it. |
− | + | ||
|- | |- | ||
| 01:15 | | 01:15 | ||
− | | Now let us see how to store a number. | + | | Now, let us see how to store a number. |
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| 01:20 | | 01:20 | ||
− | | | + | | '''int distance''' equal to '''28'''; |
− | + | ||
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| 01:27 | | 01:27 | ||
− | | This statement stores the integer value in the name '''distance.''' | + | | This statement stores the '''integer''' value in the name '''distance.''' |
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| 01:33 | | 01:33 | ||
− | | | + | | The name '''distance''' is called an '''integer variable'''. |
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| 01:47 | | 01:47 | ||
− | | '''System | + | | '''System''' dot '''out''' dot '''println''' in parentheses '''distance'''; |
− | + | ||
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| 02:01 | | 02:01 | ||
− | | This statement prints the value of the variable '''distance''' | + | | This statement prints the value of the variable '''distance'''. |
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| 02:06 | | 02:06 | ||
− | | | + | | '''Save''' the file and '''Run''' it. |
|- | |- | ||
| 02:14 | | 02:14 | ||
− | | We can see that the value ''' 28''' has been stored in distance and it has been printed. | + | | We can see that the value '''28''' has been stored in '''distance''' and it has been printed. |
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| 02:25 | | 02:25 | ||
− | | | + | | change '''28''' to '''24'''. |
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| 02:29 | | 02:29 | ||
− | | | + | | '''Save''' and '''Run'''. |
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| 02:39 | | 02:39 | ||
− | |'''int '''can also store negative values. | + | |'''int''' can also store negative values. |
− | + | ||
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| 02:42 | | 02:42 | ||
− | | Change | + | | Change '''24''' to minus 25 (-25). |
− | + | ||
− | + | ||
− | + | ||
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| 02:48 | | 02:48 | ||
− | + | | '''Save''' and '''Run'''. | |
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| 03:02 | | 03:02 | ||
− | | The | + | | The data type '''int''' is enough for most of our programming needs. |
− | + | ||
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| 03:06 | | 03:06 | ||
| But it can only store values up to a limit. | | But it can only store values up to a limit. | ||
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| 03:25 | | 03:25 | ||
− | | As we can see, there is a | + | | As we can see, there is a red line below the number which indicates an''' error'''. |
|- | |- | ||
| 03:34 | | 03:34 | ||
− | | The error message says | + | | The error message says: the number is out of range for a variable of the type '''int'''. |
− | + | ||
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| 03:42 | | 03:42 | ||
− | | '''int '''takes 32 bits of memory and can store values only from''' -2 power 31 to 2 power 31'''. | + | | '''int''' takes '''32 bits''' of memory and can store values only from '''-2 power 31''' to '''2 power 31'''. |
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| 03:49 | | 03:49 | ||
| To store large numbers, Java provides the '''long''' data type. | | To store large numbers, Java provides the '''long''' data type. | ||
− | |||
|- | |- | ||
| 03:54 | | 03:54 | ||
− | | Let us | + | | Let us use it to store a large value. |
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| 03:59 | | 03:59 | ||
− | | Change | + | | Change '''int''' to '''long''' and |
|- | |- | ||
| 04:04 | | 04:04 | ||
| add a capital '''L''' at the end of the number. | | add a capital '''L''' at the end of the number. | ||
− | |||
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| 04:11 | | 04:11 | ||
− | | Save it with''' Ctrl, S''' | + | | Save it with '''Ctrl, S'''. |
− | + | ||
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| 04:16 | | 04:16 | ||
| We see that now there is no error. | | We see that now there is no error. | ||
− | |||
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| 04:19 | | 04:19 | ||
− | | Let us run it with '''Ctrl, F11'''. The value has been printed | + | | Let us run it with '''Ctrl, F11'''. The value has been printed. |
− | + | ||
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| 04:27 | | 04:27 | ||
− | | We can see that large numbers can be stored in a long variable. | + | | We can see that large numbers can be stored in a '''long''' '''variable'''. |
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| 04:32 | | 04:32 | ||
− | | | + | | Now, let us store a decimal number in a '''int''' variable. |
− | + | ||
|- | |- | ||
| 04:37 | | 04:37 | ||
− | | Change '''long '''to '''int '''and change the number to '''23.5 | + | | Change '''long''' to '''int''' and change the number to '''23.5'''; |
|- | |- | ||
| 04:50 | | 04:50 | ||
− | | As we can see, there is an error. That is because '''int '''can only store integers. | + | | As we can see, there is an error. That is because '''int''' can only store integers. |
− | + | ||
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| 05:05 | | 05:05 | ||
| change the data type to '''float.''' | | change the data type to '''float.''' | ||
− | |||
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| 05:10 | | 05:10 | ||
− | | And add an '''f''' at the end of the value | + | | And add an '''f''' at the end of the value; |
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| 05:17 | | 05:17 | ||
− | | | + | | '''Save''' it. |
− | + | ||
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| 05:19 | | 05:19 | ||
| We see that now their is no error. | | We see that now their is no error. | ||
− | |||
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| 05:22 | | 05:22 | ||
− | | | + | | '''Run''' it with '''Control F11'''. |
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| 05:37 | | 05:37 | ||
− | | Now let us change the value of the variable distance | + | | Now, let us change the value of the variable '''distance'''. |
− | + | ||
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| 05:53 | | 05:53 | ||
− | | '''Save''' it and''' Run''' it | + | |'''Save''' it and '''Run''' it. |
− | + | ||
− | + | ||
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| 06:01 | | 06:01 | ||
− | | we see | + | | we see that the output is little different from what has been stored. |
− | + | ||
|- | |- | ||
| 06:06 | | 06:06 | ||
− | | This happens because there is a limit to the precision of a floating point number. | + | | This happens because there is a limit to the precision of a '''floating point''' number. |
− | + | ||
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| 06:18 | | 06:18 | ||
| Now let us see the naming rules for variables. | | Now let us see the naming rules for variables. | ||
− | |||
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| 06:23 | | 06:23 | ||
| Add a number '''2''' before the name. | | Add a number '''2''' before the name. | ||
− | |||
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| 06:30 | | 06:30 | ||
− | | we see that | + | | we see that there is a '''syntax error.''' |
− | + | ||
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| 06:34 | | 06:34 | ||
| This is because a variable name must only start with an '''alphabet''' or an '''underscore'''. | | This is because a variable name must only start with an '''alphabet''' or an '''underscore'''. | ||
− | |||
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| 06:40 | | 06:40 | ||
− | | But generally underscore is not used to start a variable name. | + | | But generally 'underscore' is not used to start a variable name. |
|- | |- | ||
| 06:45 | | 06:45 | ||
− | | Now let us add | + | | Now, let us add the number at the end of the variable name. |
− | + | ||
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| 06:55 | | 06:55 | ||
− | | We see that | + | | We see that there is no error. |
− | + | ||
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| 07:04 | | 07:04 | ||
− | | Now add an | + | | Now add an 'underscore' in the middle of the name, |
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| 07:15 | | 07:15 | ||
− | | we | + | | we see that there is no error |
− | + | ||
|- | |- | ||
| 07:17 | | 07:17 | ||
− | | | + | | which means an 'underscore' is permitted in a variable name. |
− | + | ||
|- | |- | ||
| 07:22 | | 07:22 | ||
− | | But any other''' punctuation''' in a variable name | + | | But any other '''punctuation''' in a variable name might give a syntax error or other errors. |
− | + | ||
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− | | | + | | 07:35 |
− | + | |This brings us to the end of the tutorial. | |
|- | |- | ||
|07:38 | |07:38 | ||
− | |In this tutorial we have learnt about the various '''numerical | + | |In this tutorial, we have learnt about the various '''numerical data types''' |
|- | |- | ||
| 07:44 | | 07:44 | ||
− | | | + | |and how to store numerical data. |
|- | |- | ||
| 07:46 | | 07:46 | ||
− | |And | + | |And we have also learnt the rules for naming a variable. |
|- | |- | ||
| 07:51 | | 07:51 | ||
| As an assignment for this tutorial, | | 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. | + | |see how they are different from '''int''' and '''float'''. |
− | + | ||
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| 08:05 | | 08:05 | ||
− | |To know more about the | + | |To know more about the Spoken Tutorial project, watch the video available at the following link. [http://spoken-tutorial.org/What_is_a_Spoken_Tutorial] |
|- | |- | ||
| 08:11 | | 08:11 | ||
− | | It | + | | It summarizes the Spoken Tutorial project. |
|- | |- | ||
| 08:14 | | 08:14 | ||
− | | If you do not have good bandwidth, you can download and watch it | + | | If you do not have good bandwidth, you can download and watch it. |
− | + | ||
|- | |- | ||
| 08:20 | | 08:20 | ||
− | | The Spoken Tutorial Project | + | | The Spoken Tutorial Project team: conducts workshops using '''spoken tutorials'''. |
− | + | ||
|- | |- | ||
| 08:24 | | 08:24 | ||
− | |Gives certificates to | + | |Gives certificates to those who pass an online test. For more details, please write to '''contact AT spoken HYPHEN tutorial DOT org.''' |
|- | |- | ||
| 08:35 | | 08:35 | ||
− | | | + | | Spoken Tutorial Project is a part of the Talk to a Teacher project. |
− | + | ||
|- | |- | ||
| 08:39 | | 08:39 | ||
− | |It supported by the | + | |It supported by the National Mission on Education through ICT, MHRD, Government of India. |
− | + | ||
|- | |- | ||
| 08:45 | | 08:45 | ||
− | |More information on this | + | |More information on this mission is available at the following link. |
|- | |- | ||
| 08:51 | | 08:51 | ||
| This tutorial has been contributed by '''TalentSprint'''. Thanks for joining. | | This tutorial has been contributed by '''TalentSprint'''. Thanks for joining. | ||
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− | |||
− | |||
|} | |} |
Latest revision as of 12:55, 28 March 2017
Time | Narration |
00:01 | Welcome to the spoken tutorial on Numerical Data types in Java. |
00:07 | In this tutorial, we will learn about: |
00:10 | The various Numerical Data types 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. |
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 tutorials, 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 (-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 might give a 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 data types |
07:44 | and how to store 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. |
08:05 | To know more about the Spoken Tutorial project, watch the video available at the following link. [1] |
08:11 | It summarizes the Spoken Tutorial project. |
08:14 | If you do not have good bandwidth, you can download and watch it. |
08:20 | The Spoken Tutorial Project team: conducts workshops using spoken tutorials. |
08:24 | Gives certificates to those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org. |
08:35 | Spoken Tutorial Project is a part of the Talk to a Teacher project. |
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. |