--- Eugene Lee <[EMAIL PROTECTED]> wrote:
> : switch (true) {
> : case ($var === 'TEST-1')?true:false:
> : case ($var === 'TEST-2')?true:false:
> : case ($var === 'TEST-2')?true:false:
> : do something
> : }
>
> Oh man, that's just sick...
Partially because it's unnecessarily complex. This is like saying:
if ($var === 'TEST-1')
{
$expression = true;
}
else
{
$expression = false;
}
if ($expression)
{
...
While the ternary operator makes this redundancy less obvious, it only adds to
the complexity and lack of readability. Consider the following code as a
substitute for the above example:
if ($var === 'TEST-1')
{
...
Hopefully that part is clear. Now, on to the original question. Try this
example:
<?
$foo = 'bar';
switch (true)
{
case ($foo === 'notbar'):
echo 'A';
break;
case ($foo === 'bar');
echo 'B';
break;
default:
echo 'C';
break;
}
?>
This should output B. You will also notice that it "works" when you switch on
$foo instead of the boolean true, but this is misleading. PHP converts $foo to
the boolean true when comparing to the expressions, because we set it to the
string bar. To understand this point further, try this example:
<?
$foo = 0;
switch ($foo)
{
case ($foo === 'notbar'):
echo 'A';
break;
case ($foo === 0);
echo 'B';
break;
default:
echo 'C';
break;
}
?>
This should also output B. That seems to be wrong, but in this case it is
comparing each expression to $foo, which is the integer 0 in this case, so it
evaluates to false. So, you will see A, because ($foo === 'notbar') also
evaluates to false.
Recap:
1. You can switch on anything, including boolean values.
2. Your cases can be expressions to be evaluated.
Hope that helps.
Chris
=====
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