Programming PHP

assigns $b the integer value of $a; $a remains the string "5". To cast the value of the
variable itself, you must assign the result of a cast back into the variable:
$a = "5"
$a = (int) $a; // now $a holds an integer
Not every cast is useful: casting an array to a numeric type gives 1, and casting an
array to a string gives "Array" (seeing this in your output is a sure sign that you’ve
printed a variable that contains an array).
Casting an object to an array builds an array of the properties, mapping property
names to values:
class Person {
var $name = "Fred";
var $age = 35;
}
$o = new Person;
$a = (array) $o;
print_r($a);
Array
(
[name] => Fred
[age] => 35
)
You can cast an array to an object to build an object whose properties correspond to
the array’s keys and values. For example:
$a = array('name' => 'Fred', 'age' => 35, 'wife' => 'Wilma');
$o = (object) $a;
echo $o->name;
Fred
Keys that aren’t valid identifiers, and thus are invalid property names, are inaccessible
but are restored when the object is cast back to an array.
Assignment Operators
Assignment operators store or update values in variables. The autoincrement and
autodecrement operators we saw earlier are highly specialized assignment operators—here
we see the more general forms. The basic assignment operator is =, but
we’ll also see combinations of assignment and binary operations, such as += and &=.
Assignment
The basic assignment operator (=) assigns a value to a variable. The lefthand operand
is always a variable. The righthand operand can be any expression—any simple
literal, variable, or complex expression. The righthand operand’s value is stored in
the variable named by the lefthand operand.
44 | Chapter 2: Language Basics
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