In the main Zend implementation there is not any difference. You can get it from the Flex description of the PHP language scanner:
<ST_IN_SCRIPTING>"!="|"<>" {
return T_IS_NOT_EQUAL;
}
Where T_IS_NOT_EQUAL
is the generated token. So the Bison parser does not distinguish between <>
and !=
tokens and treats them equally:
%nonassoc T_IS_EQUAL T_IS_NOT_EQUAL T_IS_IDENTICAL T_IS_NOT_IDENTICAL
%nonassoc '<' T_IS_SMALLER_OR_EQUAL '>' T_IS_GREATER_OR_EQUAL