php classes exception handling question
There's an open book quiz for a job application I'm doing, and it's obviously highlighted a shortcoming in my php knowledge.
Note, I'm not asking for the answer directly, I'm asking to be shown what I'm misunderstanding/lacking in how to answer it. The question is:
3. Finish the following class to print "Person->name has been zapped" when the
following is executed on a Person object: print $person;
class Person{
private $name = ''开发者_如何学C;
public function __construct($name){
$this->name = $name;
}
}
$person = new Person('fred');
print $person; // fred has been zapped
Now, either there's some way of adding exception handling to the class (though I would have thought 'print' would be the thing throwing the exception, or I'm just misunderstanding the question. I do know (from a quick test) that putting the print in a try..catch still causes the program to fail with a "catchable fatal error" (my catch did not fire).
What should I be reading up on ?
David
Hmm, sounds more like they're looking for your knowledge of PHP5 classes. I'd suggest taking a look at PHP's magic methods for more insight into how to accomplish what you're trying to do.
Basically, you're looking to have a printable representation of the object in question.
When you try to echo/output an object, the magic method __toString() is called -- if its defined for the class that the object is an instance of.
Here, you'd have to modify the class, to add the definition of that __toString
method, that will return the name, and the "has been zapped" portion of string :
class Person{
private $name = '';
public function __construct($name){
$this->name = $name;
}
public function __toString() {
return $this->name . ' has been zapped';
}
}
$person = new Person('fred');
print $person; // fred has been zapped
And you get the expected output :
fred has been zapped
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