Java/C2/Primitive-type-conversions/English

Title of script: Type Conversion in Java

Author: TalentSprint

Keywords: datatype, int, float, char, conversion, video tutorial

Visual Cue	Description
Slide 1 Welcome	Welcome to the spoken tutorial on Type Conversion in Java.
Slide 2 Learning Outcomes	In this tutorial, you will learn: How to convert data from one data type to another. the two types of conversion, namely implicit and explicit conversion. How to convert strings to numbers
Slide 3 Tools Used	For this tutorial we are using Ubuntu 11.10 JDK 1.6 Eclipse 3.7
Slide 4 Prerequisites	To follow this tutorial, you must have knowledge of data types in Java. If not, for relevant tutorial please visit our website as shown
Slide 5 Type Conversion	Type conversion means converting data from one data type to another. Let us see how it it done. Switch to Eclipse
Minimize Slides and open Eclipse Eclipse should contain the following code public class TypeConversion { public static void main(String[] args) { } }	Here we have the Eclipse IDE and the skeleton required for the rest of the code. I have created a class TypeConversion and added the main method to it. Now let us create a few variables.
In the main method, type int a = 5; float b; b = a; System.out.println(b);	int a equal to 5 float b b equal to a I have created two variables. a which is and integer and b which is a float. I’m storing the integer value in a float variable. Let us see what the float variable now contains. System dot out dot println within brackets b semicolon. Save the file and run it.
Save and run. Point to output	We can see that the integer 5 has been converted to float 5.0 This type of conversion is called implicit conversion. As the name goes, it means the value is automatically converted to suit the data type. Now let us convert float to an int, using same method.
Change a = 5 to a Change b to b = 2.5f; Change b = a to a = b; Change b to a inside println Point to the cross mark on left.	Change a equal to 5 to a Change b to b equal to 2.5f; Change b equal to a to a equal to b; Let us print the value in a. Change b to a. I'm now trying to store a float value in an int variable. Save the file. But as we can see, there is an error. It reads, Type mismatch: cannot convert from float to int It means Implicit conversion is possible from an int to a float but not the the other way. To convert a float to int we have to use explicit conversion. Let us see how to do so.
Change a = b to a = (int) b and point to that line	We do that by using an int in parentheses. Change a equal to b to a equal to (int) b This statement says the data in the variable b has to be converted to int data type and stored in a.
save and run. Point to output	save and run As we can see, the float value has been converted to int. But to suit the data type, the data has been changed accordingly. Explicit conversion can also be used to convert data from int to float. Let us try an example.
Change int a to int a = 5 Change float b = 2.5f to float b; Change a = (int) b to b = (float) a; Change println(a) to println(b) save and run. Point to output	Change a to a equal to 5 Change b equal to 2.5f to float b; Change a equal to (int) b to b equal to (float) a; Change println(a) to println(b) Save and Run it. As we can see, the data has been converted from int to float. Let us what happens when we convert character to integer.
Remove everything in the main function and type the following char c = 'm'; int a; a = (int) c; System.out.println(a);	char c equal to 'm'; int a; a equal to (int) c; System dot out dot println within brackets a. I'm converting the alphabet m to an integer and storing it in a. Let us run and see the output.
Save and run. Point to output	As we can see, the output is 109 which the ascii value of m. It means when a char is converted to int, its ascii value is stored. Let us try this with a digit.
Change c = 'm' to c = ' '	Change c equal to 'm' to c equal to '5' Now I'm converting the character ‘5’ to an integer. Let us see the output.
Save and run. Point to output	As we can see, the output is 53 which is the ascii value of the character ‘5’ It is not the number 5. To get the number, we have to use a string and convert it to an integer. Now let us see how to do so.
Remove everyting in main function and type the following. String sHeight = “6”; int h = (int) sHeight; System.out.println(h);	Remove everyting in main function. Then type String sHeight equal to within double quotes 6 semicolon. Next line type int h equal to within brackets int sHeight semicolon. System dot out dot println within brackets h semicolon. I’ve created a string variable with value 6. I'm using the explicit conversion Save the file. We see that there is an error.
Point to cross mark on the left	It reads Cannot cast from String to int. This means for converting strings, we cannot use implicit or explicit conversion. It must be done by other methods.
Remove the int h... and type int h = Integer.parseInt(sHeight);	int h equal to Integer dot parseInt within brackets sHeight semicolon. We have to use the parseInt method from the Integer class to do so. Let us look at the output
Save and run. Point to output	As we can see, The string has now been converted to integer. Now what if the value was a decimal number. Let us try that.
Change sHeight = “6” to sHeight = “6.5” save and run	Change 6 to 6.5 We don't see any error as of now. Run it.
Point to console	It gives an error . This is because the parseInt function can only be used on strings that contain integers. For strings that contain floating point numbers, we have to use the parseFloat method.
Remove the line int h... and type float h = Float.parseFloat(sHeight);	Let us use it. float h equal to Float.parseFloat(sHeight)
Save and run. Point to output	We can see that string has been converted to a float. This is how we convert data from one type to another, in Java.
Minimize the Eclipse window and switch to slides. Slide 6 Summary	We have come to the end of this tutorial. In this tutorial we have learnt how to convert data from one type to another. What is meant by implicit conversion and explicit conversin and How to convert strings to numbers.
Slide 7Assignment	Read about Integer.toString and Float.toString. What do they do?
Slide 8About the Spoken Tutorial Project Watch the video available at[1]http://spoken-tutorial.org/What_is_a_Spoken_Tutorial It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it	To know more about the Spoken Tutorial project, watch the video available at the following link, that summarises the project. if you do not have good bandwidth, you can download and watch it
Slide 9Spoken Tutorial WorkshopsThe Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates for those who pass an online test For more details, please write to contact@spoken-tutorial.org	The Spoken Tutorial Project Team. Conducts workshops using spoken tutorials and gives certificates for those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org.
Slide 10Acknowledgement Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at http://spoken-tutorial.org/NMEICT-Intro	Spoken Tutorial Project is a part of the Talk to a Teacher project and is supported by the National Mission on Education through ICT, MHRD, Government of India. More information on this Mission is available at spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro
Slide 11About the contributor This tutorial has been contributed by TalentSprint www.talentsprint.com Thanks for joining	This tutorial has been contributed by TalentSprint. Thanks for joining.

Contributors and Content Editors

Chandrika, Sneha