Page 173 - DCAP404 _Object Oriented Programming

Object-oriented Programming

Notes network is a piconet, and it can consist of one master device and up to seven slave
devices.”
The book guides you to write a MIDlet to create “a simple Bluetooth dating service”,
something to help break the ice when there are people in the same room who are attracted
to each other.

This is how: “You tell the MIDlet the type of date you’re looking for, and the MIDlet will
use Bluetooth to query anybody who comes near yours for compatibility. Once
compatibility is established, your potential date’s e-mail address is displayed on your
phone.”
What happens thereafter is beyond the scope of the book. However, be prepared for
failing gracefully, when tuning performance. For, “given the paucity of memory in a
typical MIDP device, your application should be prepared for disappointment each time it
asks for memory.”
And there’s a tip as a ‘possible strategy in production programming’ - that you may
“attempt to allocate all memory up front, when the application first starts”.

8.5 Summary

 A type conversion may either be explicit or implicit, depending on whether it is ordered
by the programmer or by the compiler. Explicit type conversions (casts) are used when a
programmer want to get around the compiler’s typing system; for success in this endeavour,
the programmer must use them correctly.

 Used another constructor to build a string type object from a char* type variable.
 The general form of an overloaded casting operator function, also referred to as a conversion
function, is:

operator typename()
{
//Program statement
}
 Which form to use, depends upon where we want the type-conversion function to be
located, whether in the source class or in the destination class.

8.6 Keywords

Implicit Conversion: An implicit conversion sequence is the sequence of conversions required
to convert an argument in a function call to the type of the corresponding parameter in a
function declaration.
Operator Typename(): Converts the class object of which it is a member to typename.

8.7 Review Questions

1. “In a mixed expression constants and variables are of different data types.” Justify this
statement with an example.
2. The constructor functions do not support conversion from a class to basic type. Explain
with a example.

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