Difference between revisions of "Java/C2/Primitive-type-conversions/English-timed"

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|  00:18
 
|  00:18
 
|* '''How to convert strings to numbers'''
 
|* '''How to convert strings to numbers'''
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|-
 
|-
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* '''JDK 1.6'''  and
 
* '''JDK 1.6'''  and
 
* '''Eclipse 3.7'''
 
* '''Eclipse 3.7'''
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−
 
  
 
|-
 
|-
 
| 00:33
 
| 00:33
 
|  To follow this tutorial, you must have knowledge of '''data types in Java'''.
 
|  To follow this tutorial, you must have knowledge of '''data types in Java'''.
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|-
 
|-
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|  00:47
 
|  00:47
 
|  '''Type conversion''' means converting data from one data type to another.
 
|  '''Type conversion''' means converting data from one data type to another.
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|-
 
|-
 
|  00:53
 
|  00:53
 
|Let us see how it it done.  
 
|Let us see how it it done.  
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|-
 
|-
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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.
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|-
 
|-
 
|  01:07
 
|  01:07
 
|I have created a class '''TypeConversion''' and added the main method to it.
 
|I have created a class '''TypeConversion''' and added the main method to it.
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|-
 
|-
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'''b '''''equal to''''' a'''
 
'''b '''''equal to''''' a'''
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|-
 
|-
 
|  01:33
 
|  01:33
 
|I have created two variables. '''a''' which is an integer and '''b''' which is a float.
 
|I have created two variables. '''a''' which is an integer and '''b''' which is a float.
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|-
 
|-
 
|  01:39
 
|  01:39
 
|I’m storing the integer value in a float variable.
 
|I’m storing the integer value in a float variable.
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|-
 
|-
 
|  01:43
 
|  01:43
 
|Let us see what the float variable now contains.
 
|Let us see what the float variable now contains.
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|-
 
|-
 
|  01:48
 
|  01:48
 
|'''System '''''dot''' ''out '''''dot '''''println '''''  '''''(b); ''''   
 
|'''System '''''dot''' ''out '''''dot '''''println '''''  '''''(b); ''''   
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|-
 
|-
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|  02:07
 
|  02:07
 
|  We can see that the integer '''5''' has been converted to float '''5.0'''
 
|  We can see that the integer '''5''' has been converted to float '''5.0'''
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|-
 
|-
 
|  02:13
 
|  02:13
 
|This type of conversion is called '''implicit conversion'''.
 
|This type of conversion is called '''implicit conversion'''.
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|-
 
|-
 
|  02:17
 
|  02:17
 
|As the name goes,  the value is automatically converted to suit the data type.
 
|As the name goes,  the value is automatically converted to suit the data type.
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|-
 
|-
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|  02:50
 
|  02:50
 
|Save the file.
 
|Save the file.
−
 
  
 
|-
 
|-
 
|  02:56
 
|  02:56
 
|  we  see that there is an error.
 
|  we  see that there is an error.
−
 
  
 
|-
 
|-
 
|  03:00
 
|  03:00
 
|The error message  reads, '''Type mismatch: cannot convert from float to int'''
 
|The error message  reads, '''Type mismatch: cannot convert from float to int'''
−
 
  
 
|-
 
|-
 
|  03:06
 
|  03:06
 
|It means '''Implicit conversion''' is possible only from an '''int''' to a '''float''' but not the the other way.
 
|It means '''Implicit conversion''' is possible only from an '''int''' to a '''float''' but not the the other way.
−
 
  
 
|-
 
|-
 
|  03:13
 
|  03:13
 
|To convert a '''float '''to an  '''int''' we have to use explicit conversion.
 
|To convert a '''float '''to an  '''int''' we have to use explicit conversion.
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|-
 
|-
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|  03:23
 
|  03:23
 
| We do that by using an '''int''' in parentheses, before the variable
 
| We do that by using an '''int''' in parentheses, before the variable
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|-
 
|-
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|  03:51
 
|  03:51
 
| As we can see, the '''float''' value has been converted to '''int'''.
 
| As we can see, the '''float''' value has been converted to '''int'''.
−
 
  
 
|-
 
|-
 
|  03:56
 
|  03:56
 
| But to suit the data type, the data has been changed accordingly.
 
| But to suit the data type, the data has been changed accordingly.
−
 
  
 
|-
 
|-
 
|  04:01
 
|  04:01
 
| Explicit conversion can also be used to convert data from int to float.
 
| Explicit conversion can also be used to convert data from int to float.
−
 
  
 
|-
 
|-
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|  04:42
 
|  04:42
 
| Save  the file and Run it.
 
| Save  the file and Run it.
−
 
  
 
|-
 
|-
 
|  04:51
 
|  04:51
 
|  we  see that  the int value has been converted  to  a '''float''' value  
 
|  we  see that  the int value has been converted  to  a '''float''' value  
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|-
 
|-
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|  05:53
 
|  05:53
 
|  As we can see, the output is 109 which the ascii value of '''m'''.  
 
|  As we can see, the output is 109 which the ascii value of '''m'''.  
−
 
  
 
|-
 
|-
 
|  05:58
 
|  05:58
 
| It means when a '''char''' is converted to '''int''', its ascii value is stored.
 
| It means when a '''char''' is converted to '''int''', its ascii value is stored.
−
 
  
 
|-
 
|-
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|  06:24
 
|  06:24
 
| It is not the number 5.
 
| It is not the number 5.
−
 
  
 
|-
 
|-
 
|  06:26
 
|  06:26
 
| To get the number, we have to use a string and convert it to an integer.
 
| To get the number, we have to use a string and convert it to an integer.
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|-
 
|-
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|  06:38
 
|  06:38
 
| type
 
| type
−
 
  
 
|-
 
|-
 
|  06:40
 
|  06:40
 
|'''String sHeight ''''' string form of Height equal to in double quotes '''''6 '''''  
 
|'''String sHeight ''''' string form of Height equal to in double quotes '''''6 '''''  
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−
 
  
 
|-
 
|-
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|  07:27
 
|  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
 
|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
−
 
−
 
 
   
 
   
 
|-
 
|-
 
| 07:37
 
| 07:37
 
|  And the error message reads '''Cannot cast from String to int.'''  
 
|  And the error message reads '''Cannot cast from String to int.'''  
−
 
  
 
|-
 
|-
 
|  07:42
 
|  07:42
 
|This means for converting strings, we cannot use implicit or explicit conversion.
 
|This means for converting strings, we cannot use implicit or explicit conversion.
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|-
 
|-
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|  08:21
 
|  08:21
 
|Save the file and run it  
 
|Save the file and run it  
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−
 
  
 
|-
 
|-
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|-
 
|-
 
|  08:49
 
|  08:49
−
| Save the file and run it
+
| Save the file and run it.
−
 
+
  
 
|-
 
|-
 
|  08:55
 
|  08:55
−
|  We see that again the string containing  the number has been successfully converted to an integer
+
|  We see that again the string containing  the number has been successfully converted to an integer.
 
|-
 
|-
 
|  09:03
 
|  09:03
−
|Now let us see what happens if the strings is a floating point number
+
|Now let us see what happens if the strings is a floating point number.
 
|-
 
|-
 
|  09:10  
 
|  09:10  
−
|Change''' 6543 to65.43'''.So we have a floating point number in the strings and we are converting it to an integer
+
|Change '''6543''' to '''65.43'''. So we have a floating point number in the strings and we are converting it to an integer.
 
|-
 
|-
 
|  09:22
 
|  09:22
−
|Save the file run it.
+
|'''Save''' the file, '''run''' it.
−
+
 
   
 
   
 
|-
 
|-
 
|  09:31
 
|  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
+
|  We see that there is an error. This happens because we cannot convert a  string  which contains '''floating point number''' to an '''integer'''.
−
 
+
  
 
|-
 
|-
 
|  09:41
 
|  09:41
−
| We have to convert it to  a float.Let us see how to do so;
+
| We have to convert it to  a '''float'''. Let us see how to do so;
 
|-
 
|-
 
|  09:45
 
|  09:45
−
|First data type should be float,
+
|First data type should be '''float''',
 
|-
 
|-
 
|  09:51
 
|  09:51
−
|Second we will use ''' float . parsefloat'''
+
|Second we will use '''float. parsefloat'''.
 
|-
 
|-
 
|  10:07
 
|  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.
+
|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
 
|  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.
+
|'''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
 
|  10:33
−
|And this is how we do '''implicit and explicit conversion and How do we converts strings to numbers'''.
+
|And this is how we do implicit and explicit conversion and How do we converts strings to numbers'''.
 
|-
 
|-
 
|  10:45
 
|  10:45
−
|   This brings us to  the end of the tutorial.  
+
| This brings us to  the end of the tutorial.  
  
 
|-
 
|-
 
|  10:48
 
|  10:48
−
|In this tutorial we have learnt how to convert '''data from one type to another'''.  
+
|In this tutorial we have learnt: how to convert data from one type to another.  
 
|-
 
|-
 
| 10:54
 
| 10:54
−
| What is meant by implicit and  explicit conversion  
+
| What is meant by '''implicit''' and  '''explicit''' conversion.
 
|-
 
|-
 
| 10:57
 
| 10:57
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|-
 
|-
 
| 11:01
 
| 11:01
−
|  |As an assignment for this tutorial Read about the '''Integer.toString''' and '''Float.toString. '''
+
|  |As an assignment for this tutorial, read about the '''Integer.toString''' and '''Float.toString.'''
−
 
+
  
 
|-
 
|-
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|-
 
|-
 
|  11:14
 
|  11:14
−
|  To know more about the '''Spoken Tutorial''' project, watch the video available at the following link,
+
|  To know more about the 'Spoken Tutorial' project, watch the video available at the following link.
 
|-
 
|-
 
| 11:20
 
| 11:20
−
| It  summarises the spoken- tutorial project.
+
| It  summarizes the spoken- tutorial project.
  
 
|-
 
|-
 
|  11:23
 
|  11:23
−
|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.
  
 
|-
 
|-
 
|    11:27
 
|    11:27
−
| The Spoken Tutorial Project Team. Conducts workshops using '''spoken tutorials'''
+
| The Spoken Tutorial Project Team. Conducts workshops using 'spoken tutorials'.
 
|-
 
|-
 
| 11:31
 
| 11:31
Line 421: Line 376:
 
|-
 
|-
 
|  11:40
 
|  11:40
−
|The   '''Spoken Tutorial '''Project is a part of the '''Talk to a Teacher''' project   
+
|The 'Spoken Tutorial' Project is a part of the 'Talk to a Teacher' project.  
 
|-
 
|-
 
|  11:44
 
|  11:44
−
|It is supported by the'''National Mission on Education through ICT, MHRD, Government of India.  
+
|It is supported by the National Mission on Education through ICT, MHRD, Government of India.  
 
|-
 
|-
 
|  11:50
 
|  11:50
−
|'''More information on this Mission is available at the following link '''spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro'''
+
|More information on this mission is available at the following link '''spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro'''.
  
 
|-
 
|-
 
| 11:55
 
| 11:55
 
|  This tutorial has been contributed by '''TalentSprint'''. Thanks for joining.
 
|  This tutorial has been contributed by '''TalentSprint'''. Thanks for joining.
−
 
−
 
−
 
  
 
|}
 
|}

Revision as of 10:00, 21 March 2015

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
00:23 For this tutorial we are using
  • Ubuntu 11.10
  • JDK 1.6 and
  • Eclipse 3.7
00:33 To follow this tutorial, you must have knowledge of data types in Java.
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.
00:53 Let us see how it it done.
00:55 Switch to Eclipse
01:02 Here we have the Eclipse IDE and the skeleton required for the rest of the code.
01:07 I have created a class TypeConversion and added the main method to it.
01:13 Now let us create a few variables.
01:19 int a equal to 5

float b

b equal to a

01:33 I have created two variables. a which is an integer and b which is a float.
01:39 I’m storing the integer value in a float variable.
01:43 Let us see what the float variable now contains.
01:48 System dot out dot println (b); '
01:58 Save the file and run it.
02:07 We can see that the integer 5 has been converted to float 5.0
02:13 This type of conversion is called implicit conversion.
02:17 As the name goes, the value is automatically converted to suit the data type.
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.
02:56 we see that there is an error.
03:00 The error message reads, Type mismatch: cannot convert from float to int
03:06 It means Implicit conversion is possible only from an int to a float but not the the other way.
03:13 To convert a float to an int we have to use explicit conversion.
03:17 Let us see how to do so.
03:23 We do that by using an int in parentheses, before the variable
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.
03:56 But to suit the data type, the data has been changed accordingly.
04:01 Explicit conversion can also be used to convert data from int to float.
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.
04:51 we see that the int value has been converted to a float value
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.
05:58 It means when a char is converted to int, its ascii value is stored.
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.
06:26 To get the number, we have to use a string and convert it to an integer.
06:31 Now let us see how to do so.
06:33 Clean up the main function
06:38 type
06:40 String sHeight string form of Height equal to in double quotes 6
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
07:37 And the error message reads Cannot cast from String to int.
07:42 This means for converting strings, we cannot use implicit or explicit conversion.
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
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.
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 to 65.43. 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.
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.
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.
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 summarizes the spoken- tutorial project.
11:23 If you do not have good bandwidth, you can download and watch it.
11:27 The Spoken Tutorial Project Team. Conducts workshops using 'spoken tutorials'.
11:31 Gives certificates for those who pass an online test.
11:34 For more details, please write to contact AT spoken HYPHEN tutorial DOT org.
11:40 The 'Spoken Tutorial' Project is a part of the 'Talk to a Teacher' project.
11:44 It is supported by the National 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.

Contributors and Content Editors

Gaurav, Kavita salve, PoojaMoolya, Priyacst, Sandhya.np14, Sneha

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