parsing - PHP parse/syntax errors; and how to solve them

Solution:

What are the syntax errors?

PHP belongs to the C-style and imperative programming languages. It has rigid grammar rules, which it cannot recover from when encountering misplaced symbols or ident{-code-18}-code-11}iers. It can{-code-18}-code-8}t guess your coding intentions.

Most important tips

There are a few basic precautions you can always take:

• Use proper code indentation, or adopt any lofty coding style. Readability prevents irregularities.

• Use an with syntax highlighting. Which also help with parentheses/bracket balancing.

  

• Read the language reference and examples in the manual. Twice, to become somewhat proficient.

How to interpret parser errors

A typical syntax error message reads:

Parse error: syntax error, unexpected {-code-18}-code-4{-code-18}-code-5}-code-2{-code-18}-code-5}, expecting {-code-18}-code-8}{-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5}{-code-18}-code-8} in file.php on line 217

Which lists the possible location of a syntax mistake. See the mentioned file name and line number.

A moniker such as{-code-18}-code-4{-code-18}-code-5}-code-2{-code-18}-code-5} explains which symbol the parser/tokenizer couldn{-code-18}-code-8}t process finally. This isn{-code-18}-code-8}t necessarily the cause of the syntax mistake, however.

It{-code-18}-code-8}s important to look into previous code lines as well. Often syntax errors are just mishaps that happened earlier. The error line number is just where the parser conclusively gave up to process it all.

Solving syntax errors

There are many approaches to narrow down and fix syntax hiccups.

• Open the mentioned source file. Look at the mentioned code line.

  • For runaway strings and misplaced operators, this is usually where you find the culprit.

  • Read the line left to right and imagine what each symbol does.

• More regularly you need to look at preceding lines as well.

  • In particular, missing{-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5} semicolons are missing at the previous line ends/statement. (At least from the stylistic viewpoint. )

  • If{-code-18}-code-4{-code-18}-code-5} code blocks{-code-18}-code-5} are incorrectly closed or nested, you may need to investigate even further up the source code. Use proper code indentation to simpl{-code-18}-code-11}y that.

• Look at the syntax colorization!

  • Strings and variables and constants should all have d{-code-18}-code-11}ferent colors.

  • Operators{-code-18}-code-6} should be tinted distinct as well. Else they might be in the wrong context.

  • If you see string colorization extend too far or too short, then you have found an unescaped or missing closing{-code-18}-code-7} or{-code-18}-code-8} string marker.

  • Having two same-colored punctuation characters next to each other can also mean trouble. Usually, operators are lone {-code-18}-code-11} it{-code-18}-code-8}s not{-code-18}-code-9},{-code-18}-code-10}, or parentheses following an operator. Two strings/ident{-code-18}-code-11}iers directly following each other are incorrect in most contexts.

• Whitespace is your friend. Follow any coding style.

• Break up long lines temporarily.

  • You can freely add newlines between operators or constants and strings. The parser will then concretize the line number for parsing errors. Instead of looking at the very lengthy code, you can isolate the missing or misplaced syntax symbol.

  • Split up complex{-code-18}-code-11} statements into distinct or nested{-code-18}-code-11} conditions.

  • Instead of lengthy math formulas or logic chains, use temporary variables to simpl{-code-18}-code-11}y the code. (More readable = fewer errors.)

  • Add newlines between:

    1. The code you can easily ident{-code-18}-code-11}y as correct,
    2. The parts you{-code-18}-code-8}re unsure about,
    3. And the lines which the parser complains about.
       

    Partitioning up long code blocks really helps to locate the origin of syntax errors.

• Comment out offending code.

  • If you can{-code-18}-code-8}t isolate the problem source, start to comment out (and thus temporarily remove) blocks of code.

  • As soon as you got rid of the parsing error, you have found the problem source. Look more closely there.

  • Sometimes you want to temporarily remove complete function/method blocks. (In case of unmatched curly braces and wrongly indented code.)

  • When you can{-code-18}-code-8}t resolve the syntax issue, try to rewrite the commented out sections from scratch.

• As a newcomer, avoid some of the confusing syntax constructs.

  • The ternary{-code-18}-code-13} condition operator can compact code and is useful indeed. But it doesn{-code-18}-code-8}t aid readability in all cases. Prefer plain{-code-18}-code-11} statements while unversed.

  • PHP{-code-18}-code-8}s alternative syntax ({-code-18}-code-11}:/else{-code-18}-code-11}:/end{-code-18}-code-11}{-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5}) is common for templates, but arguably less easy to follow than normal{-code-18}-code-4{-code-18}-code-5} code{-code-18}-code-5} blocks.

• The most prevalent newcomer mistakes are:

  • Missing semicolons{-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5} for terminating statements/lines.

  • Mismatched string quotes for{-code-18}-code-7} or{-code-18}-code-8} and unescaped quotes within.

  • Forgotten operators, in particular for the string. concatenation.

  • Unbalanced( parentheses). Count them in the reported line. Are there an equal number of them?

• Don{-code-18}-code-8}t forget that solving one syntax problem can uncover the next.

  • If you make one issue go away, but other crops up in some code below, you{-code-18}-code-8}re mostly on the right path.

  • If after editing a new syntax error crops up in the same line, then your attempted change was possibly a failure. (Not always though.)

• Restore a backup of previously working code, {-code-18}-code-11} you can{-code-18}-code-8}t fix it.

  • Adopt a source code versioning system. You can always view ad{-code-18}-code-11}f of the broken and last working version. Which might be enlightening as to what the syntax problem is.
    

• Invisible stray Unicode characters: In some cases, you need to use a hexeditor or d{-code-18}-code-11}ferent editor/viewer on your source. Some problems cannot be found just from looking at your code.

  • Try as the first measure to find non-ASCII symbols.

  • In particular BOMs, zero-width spaces, or non-breaking spaces, and smart quotes regularly can find their way into the source code.

• Take care of which type of linebreaks are saved in files.

  • PHP just honors \n newlines, not \r carriage returns.

  • Which is occasionally an issue for MacOS users (even on OS {-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5} X for misconfigured editors).

  • It often only surfaces as an issue when single-line// or# comments are used. Multiline/*...*/ comments do seldom disturb the parser when linebreaks get ignored.

• If your syntax error does not transmit over the web: It happens that you have a syntax error on your machine. But posting the very same file online does not exhibit it anymore. Which can only mean one of two things:

  • You are looking at the wrong file!

  • Or your code contained invisible stray Unicode (see above). You can easily find out: Just copy your code back from the web form into your text editor.

• Check your PHP version. Not all syntax constructs are available on every server.

  • php -v for the command line interpreter

  • <{-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5}?php phpinfo(){-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5} for the one invoked through the webserver.

  
  Those aren{-code-18}-code-8}t necessarily the same. In particular when working with frameworks, you will them to match up.

• Don{-code-18}-code-8}t use PHP{-code-18}-code-8}s reserved keywords as ident{-code-18}-code-11}iers for functions/methods, classes or constants.

• Trial-and-error is your last resort.

If all else fails, you can always google your error message. Syntax symbols aren{-code-18}-code-8}t as easy to search for (Stack Overflow itself is indexed by SymbolHound though). Therefore it may take looking through a few more pages before you find something relevant.

Further guides:

• PHP Debugging Basics by David Sklar
• Fixing PHP Errors by Jason McCreary
• PHP Errors – 10 Common Mistakes by Mario Lurig
• Common PHP Errors and Solutions
• How to Troubleshoot and Fix your WordPress Website
• A Guide To PHP Error Messages For Designers - Smashing Magazine

White screen of death

If your website is just blank, then typically a syntax error is the cause. Enable their display with:

• error_reporting = E_ALL
• display_errors = 1

In your generally, or via for mod_php, or even with FastCGI setups.

<{-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5}?php
   error_reporting(E_ALL){-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5}
   ini_set({-code-18}-code-7}display_errors{-code-18}-code-7}, 1){-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5}
   include({-code-18}-code-7}./broken-script.php{-code-18}-code-7}){-code-18}-code-4{-code-18}-code-5}-code-1{-code-18}-code-5}
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It also helps to enable PHP{-code-18}-code-8}serror_log and look into your webserver{-code-18}-code-8}s when a script crashes with HTTP 500 responses.

Solution:

I think this topic is totally overdiscussed/overcomplicated. Using an IDE is THE way to go to completely avoid any syntax errors. I would even say that working without an IDE is kind of unprofessional. Why? Because modern IDEs check your syntax after every character you type. When you code and your entire line turns red, and a big warning notice shows you the exact type and the exact position of the syntax error, then there's absolutely no need to search for another solution.

Using a syntax-checking IDE means:

You'll (effectively) never run into syntax errors again, simply because you see them right as you type. Seriously.

Excellent IDEs with syntax check (all of them are available for Linux, Windows and Mac):

1. NetBeans [free]
2. PHPStorm [$199 USD]
3. Eclipse with PHP Plugin [free]
4. Sublime [$80 USD] (mainly a text editor, but expandable with plugins, like PHP Syntax Parser)

Solution:

Unexpected{-code-11}-code-1}

These days, the unexpected{-code-11}-code-1} array bracket is commonly seen on outdated PHP versions. The short array syntax is available since PHP >= 5.4. Older installations only support{-code-11}-code-3}.

{-code-17}php53 = array{-code-12}1, 2, 3{-code-23};
{-code-17}php54 = {-code-11}-code-1}1, 2, 3{-code-21};
         ⇑
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Array function result dereferencing is likewise not available for older PHP versions:

{-code-17}result = get_whatever{-code-12}{-code-23}{-code-11}-code-1}"key"{-code-21};
                      ⇑
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Reference - What does this error mean in PHP? - "Syntax error, unexpected shows the most common and practical workarounds.

• PHP syntax for dereferencing function result → possible as of PHP 5.4
• PHP syntax error, unexpected '{-code-11}-code-1}'
• Shorthand for arrays: is there a literal syntax like {-code-11}} or {-code-11}-code-1}{-code-21}?
• PHP 5.3.10 vs PHP 5.5.3 syntax error unexpected '{-code-11}-code-1}'
• PHP Difference between {-code-11}-code-3} and {-code-11}-code-1}{-code-21}
• PHP Array Syntax Parse Error Left Square Bracket "{-code-11}-code-1}"

BTW, there are also preprocessors and PHP 5.4 syntax down-converters if you're really clingy with older + slower PHP versions.

Other causes for Unexpected{-code-11}-code-1} syntax errors

If it's not the PHP version mismatch, then it's oftentimes a plain typo or newcomer syntax mistake:

• You can't use array property declarations/expressions in classes, not even in PHP 7.

  protected {-code-17}var{-code-11}-code-1}"x"{-code-21} = "Nope";
                ⇑
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• Confusing{-code-11}-code-1} with opening curly braces{-code-11} or parentheses{-code-12} is a common oversight.

  foreach {-code-11}-code-1}{-code-17}a as {-code-17}b{-code-23}
          ⇑
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  Or even:

  function foobar{-code-11}-code-1}{-code-17}a, {-code-17}b, {-code-17}c{-code-21} {-code-11}
                 ⇑
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• Or trying to dereference {-code-16}ants {-code-12}before PHP 5.6{-code-23} as arrays:

  {-code-17}var = {-code-16}{-code-11}-code-1}123{-code-21};
         ⇑
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  At least PHP interprets that{-code-16} as a {-code-16}ant name.

  If you meant to access an array variable {-code-12}which is the typical cause here{-code-23}, then add the leading{-code-17} sigil - so it becomes a{-code-17}varname.

• You are trying to use the{-code-19} keyword on a member of an associative array. This is not valid syntax:

  {-code-19} {-code-17}var{-code-11}-code-1}'key'{-code-21};
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Unexpected{-code-21} closing square bracket

This is somewhat rarer, but there are also syntax accidents with the terminating array{-code-21} bracket.

• Again mismatches with{-code-23} parentheses or} curly braces are common:

  function foobar{-code-12}{-code-17}a, {-code-17}b, {-code-17}c{-code-21} {-code-11}
                            ⇑
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• Or trying to end an array where there isn't one:

  {-code-17}var = 2{-code-21};
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  Which often occurs in multi-line and nested array declarations.

  {-code-17}array = {-code-11}-code-1}1,{-code-11}-code-1}2,3{-code-21},4,{-code-11}-code-1}5,6{-code-11}-code-1}7,{-code-11}-code-1}8{-code-21},{-code-11}-code-1}9,10{-code-21}{-code-21},11{-code-21},12{-code-21}{-code-21},15{-code-21};
                                               ⇑
  Copy code

  If so, use your IDE for bracket matching to find any premature{-code-21} array closure. At the very least use more spacing and newlines to narrow it down.

Solution:

Unexpected {-code-1{-code-16}

An "{-code-13{-code-16}unexpected{-code-1{-code-16}"{-code-13{-code-16} means that there's a literal{-code-2{-code-16} name{-code-8{-code-16} which doesn't fit into the current expression/statement structure{-code-4{-code-16}

1. Missing semicolon

   It most commonly indicates a missing semicolon in the previous line{-code-4{-code-16} Variable assignments following a statement are a good indicator where to look:

           {-code-3{-code-16}
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2. String concatenation

   A frequent mishap are string concatenations with {-code-14{-code-16}gotten{-code-4{-code-16} operator:

                                   {-code-5{-code-16}
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   Btw{-code-8{-code-16} you should prefer string interpolation {-code-23}basic variables in double quotes) whenever that helps readability{-code-4{-code-16} Which avoids these syntax issues{-code-4{-code-16}

   String interpolation is a scripting language core feature{-code-4{-code-16} No shame in utilizing it{-code-4{-code-16} Ignore any micro-optimization advise about variable{-code-4{-code-16} concatenation being faster{-code-4{-code-16} It's not{-code-4{-code-16}

3. Missing expression operators

   Of course the same issue can arise in other expressions{-code-8{-code-16} {-code-14{-code-16} instance arithmetic operations:

               {-code-7{-code-16}
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   PHP can't guess here {-code-19} the variable should have been added{-code-8{-code-16} subtracted or compared etc{-code-4{-code-16}

4. Lists

   Same {-code-14{-code-16} syntax {-code-11{-code-16}s{-code-8{-code-16} like in array populations{-code-8{-code-16} where the parser also indicates an expected comma{-code-8{-code-16} {-code-14{-code-16} example:

                                          ⇓
    $var = array{-code-23}"{-code-13{-code-16}1"{-code-13{-code-16} =>{-code-13{-code-16} $val{-code-8{-code-16} $val2{-code-8{-code-16} $val3 $val4){-code-13{-code-16}
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   Or functions parameter {-code-11{-code-16}s:

                                    ⇓
    function myfunc{-code-23}$param1{-code-8{-code-16} $param2 $param3{-code-8{-code-16} $param4)
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   Equivalently do you see this with{-code-11{-code-16} or{-code-12{-code-16} statements{-code-8{-code-16} or when lacking a{-code-13{-code-16} semicolon in a{-code-14{-code-16} loop{-code-4{-code-16}

5. Class declarations

   This parser error also occurs in class declarations{-code-4{-code-16} You can only assign static constants{-code-8{-code-16} not expressions{-code-4{-code-16} Thus the parser complains about variables as assigned data:

    class xyz {      ⇓
        var $value = $_GET["{-code-13{-code-16}input"{-code-13{-code-16}]{-code-13{-code-16}
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   Unmatched{-code-16} closing curly braces can in particular lead here{-code-4{-code-16} If a method is terminated too early {-code-23}use proper indentation!){-code-8{-code-16} then a stray variable is commonly misplaced into the class declaration body{-code-4{-code-16}

6. Variables after ident{-code-19}iers

   You can also never have a variable follow an ident{-code-19}ier directly:

                 ⇓
    $this->{-code-13{-code-16}myFunc$VAR{-code-23}){-code-13{-code-16}
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   Btw{-code-8{-code-16} this is a common example where the intention was to use variable variables perhaps{-code-4{-code-16} In this case a variable property lookup with$this->{-code-13{-code-16}{"{-code-13{-code-16}myFunc$VAR"{-code-13{-code-16}{-code-16}{-code-23}){-code-13{-code-16} {-code-14{-code-16} example{-code-4{-code-16}

   Take in mind that using variable variables should be the exception{-code-4{-code-16} Newcomers often try to use them too casually{-code-8{-code-16} even when arrays would be simpler and more appropriate{-code-4{-code-16}

7. Missing parentheses after language constructs

   Hasty typing may lead to {-code-14{-code-16}gotten opening or closing parenthesis {-code-14{-code-16}{-code-19} and{-code-14{-code-16} and{-code-14{-code-16}each statements:

           ⇓
    {-code-14{-code-16}each $array as $key) {
   Copy code

   Solution: add the missing opening{-code-23} between statement and variable{-code-4{-code-16}

                          ⇓
    {-code-19} {-code-23}$var = pdo_query{-code-23}$sql) {
         $result = …
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   The curly{ brace does not open the code block{-code-8{-code-16} without closing the{-code-19} expression with the) closing parenthesis first{-code-4{-code-16}

8. Else does not expect conditions

        ⇓
   else {-code-23}$var >{-code-13{-code-16}= 0)
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   Solution: Remove the conditions fromelse or use {-code-4{-code-16}

9. Need brackets {-code-14{-code-16} closure

        ⇓
   function{-code-23}) use $var {{-code-16}
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   Solution: Add brackets around$var{-code-4{-code-16}

10. Invisible whitespace

    As mentioned in the reference answer on "{-code-13{-code-16}Invisible stray Unicode"{-code-13{-code-16} {-code-23}such as a non-breaking space){-code-8{-code-16} you might also see this error {-code-14{-code-16} unsuspecting code like:

    <{-code-13{-code-16}?php
                              ⇐
    $var = new PDO{-code-23}{-code-4{-code-16}{-code-4{-code-16}{-code-4{-code-16}){-code-13{-code-16}
    Copy code

    It's rather prevalent in the start of files and {-code-14{-code-16} copy-and-pasted code{-code-4{-code-16} Check with a hexeditor{-code-8{-code-16} {-code-19} your code does not visually appear to contain a syntax issue{-code-4{-code-16}

See also

• Search: unexpected {-code-1{-code-16}

Solution:

Unexpected T_CONSTANT_ENCAPSED_STRING
Unexpected T_ENCAPSED_AND_WHITESPACE

The unwieldy namesT_CONSTANT_ENCAPSED_STRING andT_ENCAPSED_AND_WHITESPACE refer to quoted "string" literals.

They're used in different contexts, but the syntax issue are quite similar. T_ENCAPSED… warnings occur in double quoted string context, while T_CONSTANT… strings are often astray in plain PHP expressions or statements.

1. Incorrect variable interpolation

   And it comes up most frequently for incorrect PHP variable interpolation:

                             ⇓     ⇓
   echo "Here comes a $wrong['array'] access";
   Copy code

   Quoting arrays keys is a must in PHP context. But in double quoted strings (or HEREDOCs) this is a mistake. The parser complains about the contained single quoted'string', because it usually expects a literal identifier / key there.

   More precisely it's valid to use PHP2-style simple syntax within double quotes for array references:

   echo "This is only $valid[here] ...";
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   Nested arrays or deeper object references however require the complex curly string expression syntax:

   echo "Use {$array['as_usual']} with curly syntax.";
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   If unsure, this is commonly safer to use. It's often even considered more readable. And better IDEs actually use distinct syntax colorization for that.

2. Missing concatenation

   If a string follows an expression, but lacks a concatenation or other operator, then you'll see PHP complain about the string literal:

                          ⇓
   print "Hello " . WORLD  " !";
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   While it's obvious to you and me, PHP just can't guess that the string was meant to be appended there.

3. Confusing string quote enclosures

   The same syntax error occurs when confounding string delimiters. A string started by a single' or double" quote also ends with the same.

                   ⇓
   print "<a href="' . $link . '">click here</a>";
         ⌞⎽⎽⎽⎽⎽⎽⎽⎽⌟⌞⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⌟⌞⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⌟
   Copy code

   That example started with double quotes. But double quotes were also destined for the HTML attributes. The intended concatenation operator within however became interpreted as part of a second string in single quotes.

   Tip: Set your editor/IDE to use slightly distinct colorization for single and double quoted strings. (It also helps with application logic to prefer e.g. double quoted strings for textual output, and single quoted strings only for constant-like values.)

   This is a good example where you shouldn't break out of double quotes in the first place. Instead just use proper for the HTML attributes´ quotes:

   print "<a href=\"{$link}\">click here</a>";
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   While this can also lead to syntax confusion, all better IDEs/editors again help by colorizing the escaped quotes differently.

4. Missing opening quote

   Equivalently are forgotten opening a recipe for parser errors:

                  ⇓
    make_url(login', 'open');
   Copy code

   Here the', ' would become a string literal after a bareword, when obviouslylogin was meant to be a string parameter.

5. Array lists

   If you miss a, comma in an array creation block, the parser will see two consecutive strings:

   array(               ⇓
        "key" => "value"
        "next" => "....",
   );
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   Note that the last line may always contain an extra comma, but overlooking one in between is unforgivable. Which is hard to discover without syntax highlighting.

6. Function parameter lists

   The same thing for function calls:

                            ⇓
   myfunc(123, "text", "and"  "more")
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7. Runaway strings

   A common variation are quite simply forgotten string terminators:

                                   ⇓
   mysql_evil("SELECT * FROM stuffs);
   print "'ok'";
         ⇑
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   Here PHP complains about two string literals directly following each other. But the real cause is the unclosed previous string of course.

8. HEREDOC indentation

   Prior PHP 7.3, the heredoc string end delimiter can't be prefixed with spaces:

   print <<< HTML
       <link..>
       HTML;
      ⇑
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   Solution: upgrade PHP or find a better hoster.

See also

• Interpolation (double quoted string) of Associative Arrays in PHP
• PHP - syntax error, unexpected T_CONSTANT_ENCAPSED_STRING
• Syntax error, unexpected T_CONSTANT_ENCAPSED_STRING in PHP
• Unexpected T_CONSTANT_ENCAPSED_STRING error in SQL Query

Solution:

Unexpected

is a bit of a misnomer. It does not refer to a quoted{-code-2}. It means a raw identifier was encountered. This can range from{-code-3} words to leftover{-code-4} or function names, forgotten unquoted strings, or any plain text.

1. Misquoted strings

   This syntax error is most common for misquoted string values however. Any unescaped and stray{-code-5} or{-code-6} quote will form an invalid expression:

                  ⇓                  ⇓
    {-code-11} {-code-5}<{-code-29}a href={-code-5}http://example.com{-code-5}>{-code-29}click here<{-code-29}/a>{-code-29}{-code-5}{-code-29}
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   Syntax highlighting will make such mistakes super obvious. It{-code-6}s important to remember to use backslashes for escaping{-code-33}{-code-5} double quotes, or{-code-33}{-code-6} single quotes - depending on which was used as string enclosure.

   • For convenience you should prefer outer single quotes when outputting plain HTML with double quotes within.
   • Use double quoted strings if you want to interpolate variables, but then watch out for escaping literal{-code-5} double quotes.
   • For lengthier output, prefer multiple{-code-11}/{-code-12} lines instead of escaping in and out. Better yet consider a HEREDOC section.

   
   Another example is using PHP entry inside HTML code generated with PHP:

   {-code-14} = {-code-6}<{-code-29}div>{-code-29}some text with {-code-25}php {-code-11} {-code-6}some php entry{-code-6} ?>{-code-29}<{-code-29}/div>{-code-29}{-code-6}
   Copy code

   This happens if{-code-14} is large with many lines and developer does not see the whole PHP variable value and focus on the piece of code forgetting about its source. Example is here

   See also What is the difference between single-quoted and double-quoted strings in PHP?.

2. Unclosed strings

   If you miss a closing then a syntax error typically materializes later. An unterminated string will often consume a bit of code until the next intended string value:

                                                          ⇓
   {-code-11} {-code-5}Some text{-code-5}, {-code-32}a_variable, {-code-5}and some runaway string {-code-29}
   success({-code-5}finished{-code-5}){-code-29}
            ⇯
   Copy code

   It{-code-6}s not just literals which the parser may protest then. Another frequent variation is an for unquoted literal HTML.

3. Non-programming string quotes

   If you copy and paste code from a blog or website, you sometimes end up with invalid code. Typographic quotes aren{-code-6}t what PHP expects:

   {-code-14} = ’Something something..’ + {-code-20} ain{-code-6}t quotes”{-code-29}
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   Typographic/smart quotes are Unicode symbols. PHP treats them as part of adjoining alphanumeric text. For example{-code-20} is interpreted as a constant identifier. But any following text literal is then seen as a {-code-3}word/ by the parser.

4. The missing semicolon{-code-29} again

   If you have an unterminated expression in previous lines, then any following statement or language construct gets seen as raw identifier:

          {-code-21}
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   PHP just can{-code-6}t know if you meant to run two functions after another, or if you meant to multiply their results, add them, compare them, or only run one{-code-22} or the other.

5. Short open tags and{-code-23} headers in PHP scripts

   This is rather uncommon. But if short_open_tags are enabled, then you can{-code-6}t begin your PHP scripts with an XML declaration:

         ⇓
   {-code-23} {-code-27}={-code-5}1.0{-code-5}?>{-code-29}
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   PHP will see the{-code-25} and reclaim it for itself. It won{-code-6}t understand what the stray{-code-26} was meant for. It{-code-6}ll get interpreted as constant. But the{-code-27} will be seen as another literal/constant. And since the parser can{-code-6}t make sense of two subsequent literals/values without an expression operator in between, that{-code-6}ll be a parser failure.

6. Invisible Unicode characters

   A most hideous cause for syntax errors are Unicode symbols, such as the Write your answer