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 . "\n";
12 echo $foo->$baz[1] . "\n";
13 
14 $start = ‘b‘;
15 $end   = ‘ar‘;
16 echo $foo->{$start . $end} . "\n";
17 
18 $arr = ‘arr‘;
19 echo $foo->$arr[1] . "\n";
20 echo $foo->{$arr}[1] . "\n";
21 
22 ?>

1 I am bar.
2 I am bar.
3 I am bar.
4 I am r.
5 I am B.

 1 <?php
 2 
 3     $s = "ideone";
 4     $s1 = ‘\\Hello World $s‘;       //输出为\Hello World $s
 5     $s2 = "\\Hello World && $s";    //输出为\Hello World && ideone
 6     echo $s1;
 7     echo $s2;
 8     
 9     //另外在类似一下的字符串自我嵌套中嵌套的部分是不会迭代的而是空
10     $s3 = "Hello World $s3";        //输出为Hello World
11     echo $s3;
12 ?>