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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