PHP bool Value

In PHP, when other types of variables are converted to boolean, the following values are considered FALSE:

Boolean value: FALSE;
Integer value 0 (zero );
Floating point value: 0.0 (0 );
Null String (""), and string ("0 ");
Array that does not contain any elements;
Objects that do not include any member variables (applicable only to PHP 4.0 );
Special Type NULL (including unset variables );
SimpleXML object generated from an XML document without any tags;
All other values are considered to be TRUE (including any resources ).

Note:-1 is considered TRUE like other non-zero values (both positive and negative values!

Var_dump (bool) ""); // bool (false)
Var_dump (bool) 1); // bool (true)
Var_dump (bool)-2); // bool (true)
Var_dump (bool) "foo"); // bool (true)
Var_dump (bool) 2.3e5); // bool (true)
Var_dump (bool) array (12); // bool (true)
Var_dump (bool) array (); // bool (false)
Var_dump (bool) "false"); // bool (true)
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