Java/C2/Primitive-type-conversions/English-timed
From Script | Spoken-Tutorial
Revision as of 13:12, 16 September 2013 by Kavita salve (Talk | contribs)
Time' | Narration |
00:01 | Welcome to the spoken tutorial on Type Conversion in Java. |
00:06 | In this tutorial, we learn: |
00:08 | * How to convert data from one data type to another. |
00:13 | * the two types of conversion, namely implicit and explicit conversion. And |
00:18 | * How to convert strings to numbers
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00:23 | For this tutorial we are using
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00:33 | To follow this tutorial, you must have knowledge of data types in Java.
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00:38 | If not, for relevant tutorial please visit our website as shown |
00:47 | Type conversion means converting data from one data type to another.
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00:53 | Let us see how it it done.
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00:55 | Switch to Eclipse |
01:02 | Here we have the Eclipse IDE and the skeleton required for the rest of the code.
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01:07 | I have created a class TypeConversion and added the main method to it.
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01:13 | Now let us create a few variables. |
01:19 | int a equal to 5
float b b equal to a
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01:33 | I have created two variables. a which is an integer and b which is a float.
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01:39 | I’m storing the integer value in a float variable.
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01:43 | Let us see what the float variable now contains.
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01:48 | System dot out dot println (b); '
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01:58 | Save the file and run it. |
02:07 | We can see that the integer 5 has been converted to float 5.0
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02:13 | This type of conversion is called implicit conversion.
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02:17 | As the name goes, the value is automatically converted to suit the data type.
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02:24 | Now let us convert float to an int, using the same method. |
02:30 | Remove the 5 float b equal to 2.5f and let us store b in a and print the value of a . |
02:50 | Save the file.
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02:56 | we see that there is an error.
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03:00 | The error message reads, Type mismatch: cannot convert from float to int
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03:06 | It means Implicit conversion is possible only from an int to a float but not the the other way.
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03:13 | To convert a float to an int we have to use explicit conversion.
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03:17 | Let us see how to do so. |
03:23 | We do that by using an int in parentheses, before the variable
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03:34 | This statement says the data in the variable b has to be converted to int data type and stored in a. |
03:43 | save and run the file |
03:51 | As we can see, the float value has been converted to int.
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03:56 | But to suit the data type, the data has been changed accordingly.
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04:01 | Explicit conversion can also be used to convert data from int to float.
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04:07 | Let us try the previous example. |
04:10 | int a =5, float b, b = (float) a |
04:32 | System.out.println(b); |
04:36 | We are using Explicit conversion to convert integer to a float |
04:42 | Save the file and Run it.
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04:51 | we see that the int value has been converted to a float value
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04:58 | Let us see what happens when we convert a character to an integer. |
05:06 | int a, char c equal to in single quotes 'm';
' |
05:24 | a equal to '(int) c |
05:32 | System dot out dot println ' a. |
05:36 | We are converting the character m to an integer and printing the value |
05:43 | Let us save and run it |
05:53 | As we can see, the output is 109 which the ascii value of m.
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05:58 | It means when a char is converted to int, its ascii value is stored.
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06:03 | Let us try this with a digit. |
06:06 | char c = digit 5 |
06:11 | Save it and run it |
06:18 | As we can see, the output is 53 which is the ascii value of the character ‘5’ |
06:24 | It is not the number 5.
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06:26 | To get the number, we have to use a string and convert it to an integer.
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06:31 | Now let us see how to do so. |
06:33 | Clean up the main function |
06:38 | type
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06:40 | String sHeight string form of Height equal to in double quotes 6
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06:58 | int h equal to explicit conversion int of sHeight and |
07:11 | System dot out dot println h Save the file. |
07:27 | I’ve created a string variable with value 6 and i am trying to convert it to an integer but we see that there is an error
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07:37 | And the error message reads Cannot cast from String to int.
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07:42 | This means for converting strings, we cannot use implicit or explicit conversion.
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07:48 | It must be done by other methods. let us use them |
07:58 | Remove int sHeight and type Integer dot parseInt sHeight '. |
08:21 | Save the file and run it
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08:29 | we see that the value has been successfully converted to an integer. |
08:35 | To do this we use the parseInt method of the integer module. |
08:41 | Now let us see what happens if there are more than one digits like 6543 |
08:49 | Save the file and run it
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08:55 | We see that again the string containing the number has been successfully converted to an integer |
09:03 | Now let us see what happens if the strings is a floating point number |
09:10 | Change 6543 to65.43.So we have a floating point number in the strings and we are converting it to an integer |
09:22 | Save the file run it.
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09:31 | We see that there is an error This happens because we cannot convert a string which contains floating point number to an integer
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09:41 | We have to convert it to a float.Let us see how to do so; |
09:45 | First data type should be float, |
09:51 | Second we will use float . parsefloat |
10:07 | We are using the Parsefloat methods of the float class to convert the string containing a floating point number into an actual floating point number. |
10:18 | Save the file run it. We can see that the string containing a floating point number has been successfully converted to floating point number. |
10:33 | And this is how we do implicit and explicit conversion and How do we converts strings to numbers. |
10:45 | This brings us to the end of the tutorial. |
10:48 | In this tutorial we have learnt how to convert data from one type to another. |
10:54 | What is meant by implicit and explicit conversion |
10:57 | and How to convert strings to numbers. |
11:01 | As an assignment for this tutorial Read about the Integer.toString and Float.toString.
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11:07 | And Find out What do they do? |
11:14 | To know more about the Spoken Tutorial project, watch the video available at the following link, |
11:20 | It summarises the spoken- tutorial project. |
11:23 | if you do not have good bandwidth, you can download and watch it |
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11:40 | The Spoken Tutorial Project is a part of the Talk to a Teacher project |
11:44 | It is supported by theNational Mission on Education through ICT, MHRD, Government of India. |
11:50 | More information on this Mission is available at the following link spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro |
11:55 | This tutorial has been contributed by TalentSprint. Thanks for joining.
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Contributors and Content Editors
Gaurav, Kavita salve, PoojaMoolya, Priyacst, Sandhya.np14, Sneha