php细节1可变变量及一些细节

 1 <?php
 2 class foo {
 3     var $bar = 'I am bar.';
 4     var $arr = array('I am A.', 'I am B.', 'I am C.');
 5     var $r   = 'I am r.';
 6 }
 7 
 8 $foo = new foo();
 9 $bar = 'bar';
10 $baz = array('foo', 'bar', 'baz', 'quux');
11 echo $foo->$bar . "
";
12 echo $foo->$baz[1] . "
";
13 
14 $start = 'b';
15 $end   = 'ar';
16 echo $foo->{$start . $end} . "
";
17 
18 $arr = 'arr';
19 echo $foo->$arr[1] . "
";
20 echo $foo->{$arr}[1] . "
";
21 
22 ?>