Prev | Current Page 142 | Next

W. Jason Gilmore

"Beginning PHP and MySQL: From Novice to Professional"

This is accomplished via the
new keyword. Therefore, in the last line of the previous listing, an object of class Appliance
named blender is created.
The blender object??™s power attribute can then be set by making use of the method
setPower():
$blender->setPower("on");
Improvements to PHP??™s object-oriented development model are a highlight of
PHP 5 and are further enhanced in PHP 6. Chapters 6 and 7 are devoted to thorough
coverage of PHP??™s object-oriented development model.
CHAPTER 3 ?–  PHP BASICS 69
Converting Between Datatypes Using Type Casting
Converting values from one datatype to another is known as type casting. A variable can
be evaluated once as a different type by casting it to another. This is accomplished by
placing the intended type in front of the variable to be cast. A type can be cast by inserting
one of the operators shown in Table 3-2 in front of the variable.
Let??™s consider several examples. Suppose you??™d like to cast an integer as a double:
$score = (double) 13; // $score = 13.0
Type casting a double to an integer will result in the integer value being rounded
down, regardless of the decimal value. Here??™s an example:
$score = (int) 14.8; // $score = 14
What happens if you cast a string datatype to that of an integer? Let??™s find out:
$sentence = "This is a sentence";
echo (int) $sentence; // returns 0
In light of PHP??™s loosely typed design, it will simply return the integer value unmodified.


Pages:
130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154