1) Type conversion allows assigning a value of one type to a variable of a different type automatically if the destination type has enough space, such as assigning an int value to a byte variable. 2) Type casting involves explicitly converting the value of one type to another using syntax like (type) before assigning it to a variable, and is necessary when the automatic conversion is not possible or may lose data. 3) Both type conversion and casting in Java allow mixing data types, but type casting preserves the original value while conversion may lose data like the fractional part of a float assigned to an int.

1. Type conversion and casting features
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2. Objectives
On completion of this period, you would be able to
know :
• The type conversion and casting features
9CM604.8 2

3. Recap
• How to declare variables
• How to initialize the variables
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4. Type Conversion
• It is possible to assign a value of one type to a
variable of different type without a cast
• Java does the conversion of the assigned value
automatically
• This is known as ‘automatic type conversion’
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5. Contd..
Type Conversion
• It is possible only if the destination type has
enough space to store the source value
eg. : byte m=9;
int k=18;
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6. Contd..
Type Conversion
• The process of assigning a smaller type to a larger
one is known as ‘widening’ or ‘promotion’
• Assigning a larger type to a smaller one is known
as ‘narrowing’
• Narrowing may result in loss of information
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7. Casting
• To store a value of one type into a variable of
another type, then we must cast
• The value to be stored by preceding it with the
type name in parentheses
• The syntax is
type variable1 = (type) variable2;
eg. : int d;
double m;
int d = (double) b;
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8. Contd..
Casting
• The process of converting one data type to another
is called ‘casting’
• Casting is necessary when a method returns a type
different than we required
• Four integer types can be cast to another type
except boolean
• Casting into smaller type may result in loss of data
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9. Contd..
Casting
• The float and double can be cast to any other type
except boolean
• Casting a floating point value to an integer value
will result in loss of the fractional part
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10. Summary
• Automatic Type Conversion
• Type Casting
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11. Quiz
1.The process of converting one data type to another
is called ______
a) Casting
b) Conversion
c) Swapping
d) All the Above
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12. Frequently Asked Questions
• How can you declare a Variable
• Explain the initialization of a variable using read
statement
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