11. strrpos() and strripos() now use the entire string as a needle.  Be aware
2   that the existing scripts may no longer work as you expect.
3
4   EX :
5   <?php
6   var_dump(strrpos("ABCDEF","DEF"));
7   var_dump(strrpos("ABCDEF","DAF"));
8   ?>
9
10   Will give you different results. The former returns 3 while the latter
11   returns false rather than the position of the last occurrence of 'D'.
12   The same applies to strripos().
13
142. Illegal use of string offsets causes E_ERROR instead of E_WARNING.
15
16   EX :
17   <?php
18   $a = "foo";
19   unset($a[0][1][2]);
20   ?>
21
22   Fatal error: Cannot use string offset as an array in ... on line 1
23
243. array_merge() was changed to accept only arrays. If a non-array variable is
25   passed, a E_WARNING will be thrown for every such parameter. Be careful
26   because your code may start emitting E_WARNING out of the blue.
27
284. Be careful when porting from ext/mysql to ext/mysqli. The following
29   functions return NULL when no more data is available in the result set
30   (ext/mysql's functions return FALSE).
31
32    - mysqli_fetch_row()
33    - mysqli_fetch_array()
34    - mysqli_fetch_assoc()
35
365. PATH_TRANSLATED server variable is no longer set implicitly under
37   Apache2 SAPI in contrast to the situation in PHP 4, where it is set to the
38   same value as the SCRIPT_FILENAME server variable when it is not populated
39   by Apache.  This change was made to comply with the CGI specification.
40   Please refer to bug #23610 for further information.
41
426. Starting PHP 5.0.0 the T_ML_CONSTANT constant is no longer defined by the
43   ext/tokenizer extension. If error_reporting is set to E_ALL notices will
44   be produced. Instead of T_ML_CONSTANT for /* */ the T_COMMENT constant
45   is used, thus both // and /* */ are resolved as the T_COMMENT constant.
46   However the PHPDoc style comments /** */ ,which starting PHP 5 are parsed
47   by PHP, are recongnized as T_DOC_COMMENT.
48
497. $_SERVER should be populated with argc and argv if variables_order
50   includes "S".  If you have specifically configured your system to not
51   create $_SERVER, then of course it shouldn't be there.  The change was to
52   always make argc and argv available in the CLI version regardless of the
53   variables_order setting.  As in, the CLI version will now always populate
54   the global $argc and $argv variables.
55
568. In some cases classes must be declared before used. It only happens only
57   if some of the new features of PHP 5 are used. Otherwise the behaviour is
58   the old.
59   Example 1 (works with no errors):
60   <?php
61   $a = new a();
62   class a {
63   }
64   ?>
65
66   Example 2 (throws an error):
67   <?php
68   $a = new a();
69   interface b{
70   }
71   class a implements b {
72   }
73   ?>
74
75   Output (example 2) :
76   Fatal error: Class 'a' not found in /tmp/cl.php on line 2
77
789. get_class() starting PHP 5 returns the name of the class as it was
79   declared which may lead to problems in older scripts that rely on
80   the previous behaviour - the class name is lowercased. Expect the
81   same behaviour from get_parent_class() when applicable.
82   Example :
83   <?php
84   class FooBar {
85   }
86   class ExtFooBar extends FooBar{}
87   $a = new FooBar();
88   var_dump(get_class($a), get_parent_class($a));
89   ?>
90
91   Output (PHP 4):
92   string(6) "foobar"
93   string(9) "extfoobar"
94
95   Output (PHP 5):
96   string(6) "FooBar"
97   string(9) "ExtFooBar"
98   ----------------------------------------------------------------------
99   Example code that will break :
100   //....
101   function someMethod($p) {
102     if (get_class($p) != 'helpingclass') {
103       return FALSE;
104     }
105     //...
106   }
107   //...
108   Possible solution is to search for get_class() and get_parent_class() in
109   all your scripts and use strtolower().
110
11110. get_class_methods() returns the names of the methods of a class as they
112   declared. In PHP4 the names are all lowercased.
113   Example code :
114   <?php
115   class Foo{
116     function doFoo(){}
117     function hasFoo(){}
118   }
119   var_dump(get_class_methods("Foo"));
120   ?>
121   Output (PHP4):
122   array(2) {
123     [0]=>
124     string(5) "dofoo"
125     [1]=>
126     string(6) "hasfoo"
127   }
128   Output (PHP5):
129   array(2) {
130     [0]=>
131     string(5) "doFoo"
132     [1]=>
133     string(6) "hasFoo"
134   }
135
13611. Assignment $this is impossible. Starting PHP 5.0.0 $this has special
137    meaning in class methods and is recognized by the PHP parser. The latter
138    will generate a parse error when assignment to $this is found
139    Example code :
140    <?php
141    class Foo {
142      function assignNew($obj) {
143        $this = $obj;
144      }
145    }
146    $a = new Foo();
147    $b = new Foo();
148    $a->assignNew($b);
149    echo "I was executed\n";
150    ?>
151    Output (PHP 4):
152    I was executed
153    Output (PHP 5):
154    PHP Fatal error:  Cannot re-assign $this in /tmp/this_ex.php on line 4
155
156