Bug #75138 [Com]: Nested "IF" triggers Exception when it is before "else:" or "elseif:".

Edit report at https://bugs.php.net/bug.php?id=75138&edit=1 ID: 75138 Comment by: jcmarchi at gmail dot com Reported by: jcmarchi at gmail dot com Summary: Nested "IF" triggers Exception when it is before "else:" or "elseif:". Status: Not a bug Type: Bug Package: *Programming Data Structures Operating System: All PHP Version: Irrelevant Block user comment: N Private report: N New Comment: OMG... Let me draw a picture!!!! [ IF (CONDITION): [ ANYTHING IN HERE SHOULD BE A NESTED BLOCK FOR THE "IF" CONDITION WHEN IT IS TRUE ] ELSEIF (ANOTHER CONDITION): [ ANYTHING IN HERE SHOULD BE A NESTED BLOCK FOR THE "ELSEIF:" CONDITION WHEN IT IS TRUE ] ELSE: [ ANYTHING IN HERE SHOULD BE A NESTED BLOCK FOR THE "ELSE:" CONDITION WHEN IT IS TRUE ] ] Now, based on the nested blocks above, it should NOT fail when you NEST "whatever" statement inside! Each nested block is initiated by the ":" and end when it reaches an "ELSEIF" or an "ELSE" (each one of those having its own nested blocks again after their own ":"), or an "ENDIF" (when the first "IF" ends). It said such code should NOT fail: [ IF (CONDITION): [ ANYTHING IN HERE SHOULD BE A NESTED BLOCK FOR THE "IF" CONDITION WHEN IT IS TRUE IF (ANOTHER CONDITION) [ DO THIS; ] <--- THIS SHOULD BE NESTED INTO THE SAME LINE "IF" ] ELSEIF (ANOTHER CONDITION): [ ANYTHING IN HERE SHOULD BE A NESTED BLOCK FOR THE "ELSEIF:" CONDITION WHEN IT IS TRUE ] ELSE: [ ANYTHING IN HERE SHOULD BE A NESTED BLOCK FOR THE "ELSE:" CONDITION WHEN IT IS TRUE ] ] Or, based on your comment, this following logic should run, but provide a wrong result (and it actually works as expected): $bar = 'bar'; $foo = 'foo'; if (isset($bar)): if (isset($foo)) echo "Both are set."; echo " It actually works."; elseif (isset($foo)): echo "Only 'foo' is set."; else: echo "Only 'bar' is set."; endif; The above code will return: "Both are set. It actually works.", while based on your "thinking" it should return blank. Also, just for thinking purposes, try this (it works): $bar = 'bar'; $foo = 'foo'; if (isset($bar)): echo "It actually works. "; { if (isset($foo)) echo "Both are set."; } elseif (isset($foo)): echo "Only 'foo' is set."; else: echo "Only 'bar' is set."; endif; Does not matter how you look at it, if a nested IF statement (any coding style) precedes an "else:" or an "elseif:" statement, a DOUBLE semicolon is required to make it work (or sub-enclosure it under curly brackets). I can't believe you cannot see it. More (simplified) examples: // FAIL: $bar = 'bar'; if (true): if ($bar == 'bar') echo "Got 'bar'."; else: echo "Didn't get 'bar'."; endif; // WORKS: $bar = 'bar'; if (true): if ($bar == 'bar') echo "Got 'bar'.";; else: echo "Didn't get 'bar'."; endif; // WORKS: $bar = 'bar'; if (true): { if ($bar == 'bar') echo "Got 'bar'."; } else: echo "Didn't get 'bar'."; endif; // FAIL: $bar = 'bar'; if (true): if ($bar == 'bar') { echo "Got 'bar'."; } else: echo "Didn't get 'bar'."; endif; // WORKS: $bar = 'bar'; if (true): if ($bar == 'bar') { echo "Got 'bar'."; }; else: echo "Didn't get 'bar'."; endif; Previous Comments: ------------------------------------------------------------------------ [2017-08-30 22:02:56] spam2 at rhsoft dot net just take your code, remove any whitespace and look again at it ------------------------------------------------------------------------ [2017-08-30 21:25:00] jcmarchi at gmail dot com Sorry, but you are also missing the point... Try this: <?php $bar = 'bar'; $foo = 'foo'; if (isset($bar)): if (isset($foo)) echo "Both are set."; echo "Working now"; elseif (isset($foo)): echo "Only 'foo' is set."; else: echo "Only 'bar' is set."; endif; ?> Now, try this (also works): <?php $bar = 'bar'; $foo = 'foo'; if (isset($bar)): if (isset($foo)) echo "Both are set."; ; elseif (isset($foo)): echo "Only 'foo' is set."; else: echo "Only 'bar' is set."; endif; ?> Question is: WHY the semicolon after the last nested IF statement is needed ONLY when the last IF is immediately BEFORE an "else:" or "elseif:" statement? Or, better said: why it only fails when the immediate last command BEFORE an "else:" or "elseif:" is an IF statement without an extra (unnecessary, wrongly required) semicolon (;)? Answer: IT IS A BUG in the interpreter/parser! It is not related to "code style", or "indentation", or "coding rules", or "standards", or "language nuances", or "Solar eclipse", etc... It is related to a tested in uncountable scenarios (and real codes) where in all cases it fails exactly the same way (code example is just it: a code example). ------------------------------------------------------------------------ [2017-08-30 20:59:17] nikic@php.net The assessment of peehaa is correct. PHP is not a whitespace-sensitive language, so the way your code is actually interpreted is as follows: if (isset($bar)): if (isset($foo)) echo "Both are set."; elseif (isset($foo)): echo "Only 'foo' is set."; else: echo "Only 'bar' is set."; endif; This mixes both styles on the same if/elseif/else structure and is, as already noted, not permitted. Please see https://en.wikipedia.org/wiki/Dangling_else for more information about this ambiguity. ------------------------------------------------------------------------ [2017-08-30 20:47:27] jcmarchi at gmail dot com @peehaa. Did you actually READ the bug report????? I don't think so... IT IS A BUG! In the interpreter... The "mixed syntax" is merely an example to display the wrong requirement of the last ";" (and it WORKS). The reported bug fails regardless of the "mixed syntax". Check code examples before saying anything! BTW, it is outrageous the lack of understanding some people has when RTFM! The statement "Mixing syntaxes in the same control block is not supported" refers to the SAME LEVEL BLOCK, not to NESTED BLOCKS (the reason why IT WORKS). -- /me losing faith in the Technology world... :'( ------------------------------------------------------------------------ [2017-08-30 15:57:34] peehaa@php.net From the docs (http://php.net/manual/en/control-structures.alternative-syntax.php): > Mixing syntaxes in the same control block is not supported. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=75138 -- Edit this bug report at https://bugs.php.net/bug.php?id=75138&edit=1