意想不到的“?”

如果您试图使用<?PHP <?PHP这个错误将被返回*。

$var = 'hello '<?php echo 'world'; ?>;

*为PHP版本4.3.1,4.3.5——4.3.11 4.4.0——4.1.1 5.0.0——5.0.5 10/24/11——4.4.9 5.1.0——5.1.6 5.2.0——5.2.17 5.3.0——5.3.29 5.4.0 5.4.45,发送,5.5.38 5.6.0——5.6.40 7.0.0——7.0.33 7.1.0——7.1.33 7.2.0——7.2.34 7.3.0——7.3.31 7.4.0——7.4.24

如果您正在尝试使用空合并操作符??在php7之前的版本中，你会得到这个错误。

<?= $a ?? 2; // works in PHP 7+
<?= (!empty($a)) ? $a : 2; // All versions of PHP

意想不到的”?，期望变量

可空类型也会出现类似的错误，如下所示:

function add(?int $sum): ?int {

这再次表明使用了过时的PHP版本(CLI版本PHP -v或web服务器绑定的phpinfo();)。

对于VS Code的新手，如果你看到语法错误，检查你是否保存了文件。如果你有一个错误的语法，保存文件，然后在不保存的情况下修复语法，VS Code会继续显示错误。只有保存文件后，错误信息才会消失。

意想不到的T_IF 意想不到的T_FOREACH 意想不到的T_FOR 意想不到的T_WHILE 意想不到的T_DO 意想不到的T_ECHO

控制结构，如if、foreach、for、while、list、global、return、do、print、echo只能作为语句使用。它们通常单独驻留在一行上。

Semicolon; where you at? Pretty universally have you missed a semicolon in the previous line if the parser complains about a control statement: ⇓ $x = myfunc() if (true) { Solution: look into the previous line; add semicolon. Class declarations Another location where this occurs is in class declarations. In the class section you can only list property initializations and method sections. No code may reside there. class xyz { if (true) {} foreach ($var) {} Such syntax errors commonly materialize for incorrectly nested { and }. In particular when function code blocks got closed too early. Statements in expression context Most language constructs can only be used as statements. They aren't meant to be placed inside other expressions: ⇓ $var = array(1, 2, foreach($else as $_), 5, 6); Likewise can't you use an if in strings, math expressions or elsewhere: ⇓ print "Oh, " . if (true) { "you!" } . " won't work"; // Use a ternary condition here instead, when versed enough. For embedding if-like conditions in an expression specifically, you often want to use a ?: ternary evaluation. The same applies to for, while, global, echo and a lesser extend list. ⇓ echo 123, echo 567, "huh?"; Whereas print() is a language built-in that may be used in expression context. (But rarely makes sense.) Reserved keywords as identifiers You also can't use do or if and other language constructs for user-defined functions or class names. (Perhaps in PHP 7. But even then it wouldn't be advisable.) Your have a semi-colon instead of a colon (:) or curly bracket ({) after your control block Control structures are typically wrapped in curly braces (but colons can be used in an alternative syntax) to represent their scope. If you accidentally use a semi-colon you prematurely close that block resulting in your closing statement throwing an error.

    foreach ($errors as $error); <-- should be : or {

意外的T_CONSTANT_ENCAPSED_STRING意外的t_encapsed_and_空白

T_CONSTANT_ENCAPSED_STRING和T_ENCAPSED_AND_WHITESPACE是指带引号的“字符串”字面量。

它们在不同的上下文中使用，但语法问题非常相似。t_encaged…警告出现在双引号的字符串上下文中，而T_CONSTANT…字符串经常在普通PHP表达式或语句中出错。

Incorrect variable interpolation And it comes up most frequently for incorrect PHP variable interpolation: ⇓ ⇓ echo "Here comes a $wrong['array'] access"; 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 $valid[here] ..."; Nested arrays or deeper object references however require the complex curly string expression syntax: echo "Use {$array['as_usual']} with curly syntax."; 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. 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 " !"; While it's obvious to you and me, PHP just can't guess that the string was meant to be appended there. 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="' . $link . '">click here</a>"; ⌞⎽⎽⎽⎽⎽⎽⎽⎽⌟⌞⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⌟⌞⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⌟ That example started with double quotes. But double quotes were also destined for the HTML attributes. The intended concatenation operator within however became interpreted as part of a second string in single quotes. Tip: Set your editor/IDE to use slightly distinct colorization for single and double quoted strings. (It also helps with application logic to prefer e.g. double quoted strings for textual output, and single quoted strings only for constant-like values.) This is a good example where you shouldn't break out of double quotes in the first place. Instead just use proper \" escapes for the HTML attributes´ quotes: print "<a href=\"{$link}\">click here</a>"; While this can also lead to syntax confusion, all better IDEs/editors again help by colorizing the escaped quotes differently. Missing opening quote Equivalently are forgotten opening "/' quotes a recipe for parser errors: ⇓ make_url(login', 'open'); Here the ', ' would become a string literal after a bareword, when obviously login was meant to be a string parameter. Array lists If you miss a , comma in an array creation block, the parser will see two consecutive strings: array( ⇓ "key" => "value" "next" => "....", ); 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. Function parameter lists The same thing for function calls: ⇓ myfunc(123, "text", "and" "more") Runaway strings A common variation are quite simply forgotten string terminators: ⇓ mysql_evil("SELECT * FROM stuffs); print "'ok'"; ⇑ Here PHP complains about two string literals directly following each other. But the real cause is the unclosed previous string of course. HEREDOC indentation Prior PHP 7.3, the heredoc string end delimiter can't be prefixed with spaces: print <<< HTML <link..> HTML; ⇑ Solution: upgrade PHP or find a better hoster.

另请参阅

PHP中关联数组的插值(双引号字符串) 语法错误，意外的T_CONSTANT_ENCAPSED_STRING 语法错误，PHP中意外的T_CONSTANT_ENCAPSED_STRING SQL查询中出现意外的T_CONSTANT_ENCAPSED_STRING错误

意想不到的T_IF 意想不到的T_ELSEIF 意想不到的T_ELSE 意想不到的T_ENDIF

条件控件块if、elseif和else遵循一个简单的结构。当你遇到语法错误时，很可能只是无效的块嵌套→缺少{花括号}——或者多了一个。

Missing { or } due to incorrect indentation Mismatched code braces are common to less well-formatted code such as: if((!($opt["uniQartz5.8"]!=$this->check58)) or (empty($_POST['poree']))) {if ($true) {echo"halp";} elseif((!$z)or%b){excSmthng(False,5.8)}elseif (False){ If your code looks like this, start afresh! Otherwise it's unfixable to you or anyone else. There's no point in showcasing this on the internet to inquire for help. You will only be able to fix it, if you can visually follow the nested structure and relation of if/else conditionals and their { code blocks }. Use your IDE to see if they're all paired. if (true) { if (false) { … } elseif ($whatever) { if ($something2) { … } else { … } } else { … } if (false) { // a second `if` tree … } else { … } } elseif (false) { … } Any double } } will not just close a branch, but a previous condition structure. Therefore stick with one coding style; don't mix and match in nested if/else trees. Apart from consistency here, it turns out helpful to avoid lengthy conditions too. Use temporary variables or functions to avoid unreadable if-expressions. IF cannot be used in expressions A surprisingly frequent newcomer mistake is trying to use an if statement in an expression, such as a print statement: ⇓ echo "<a href='" . if ($link == "example.org") { echo … Which is invalid of course. You can use a ternary conditional, but beware of readability impacts. echo "<a href='" . ($link ? "http://yes" : "http://no") . "</a>"; Otherwise break such output constructs up: use multiple ifs and echos. Better yet, use temporary variables, and place your conditionals before: if ($link) { $href = "yes"; } else { $href = "no"; } echo "<a href='$href'>Link</a>"; Defining functions or methods for such cases often makes sense too. Control blocks don't return "results" Now this is less common, but a few coders even try to treat if as if it could return a result: $var = if ($x == $y) { "true" }; Which is structurally identical to using if within a string concatenation / expression. But control structures (if / foreach / while) don't have a "result". The literal string "true" would also just be a void statement. You'll have to use an assignment in the code block: if ($x == $y) { $var = "true"; } Alternatively, resort to a ?: ternary comparison. If in If You cannot nest an if within a condition either: ⇓ if ($x == true and (if $y != false)) { ... } Which is obviously redundant, because the and (or or) already allows chaining comparisons. Forgotten ; semicolons Once more: Each control block needs to be a statement. If the previous code piece isn't terminated by a semicolon, then that's a guaranteed syntax error: ⇓ $var = 1 + 2 + 3 if (true) { … } Btw, the last line in a {…} code block needs a semicolon too. Semicolon too early Now it's probably wrong to blame a particular coding style, as this pitfall is too easy to overlook: ⇓ if ($x == 5); { $y = 7; } else ← { $x = -1; } Which happens more often than you might imagine. When you terminate the if () expression with ; it will execute a void statement. The ; becomes a an empty {} of its own! The {…} block thus is detached from the if, and would always run. So the else no longer had a relation to an open if construct, which is why this would lead to an Unexpected T_ELSE syntax error. Which also explains a likewise subtle variation of this syntax error: if ($x) { x_is_true(); }; else { something_else(); }; Where the ; after the code block {…} terminates the whole if construct, severing the else branch syntactically. Not using code blocks It's syntactically allowed to omit curly braces {…} for code blocks in if/elseif/else branches. Which sadly is a syntax style very common to unversed coders. (Under the false assumption this was quicker to type or read). However that's highly likely to trip up the syntax. Sooner or later additional statements will find their way into the if/else branches: if (true) $x = 5; elseif (false) $x = 6; $y = 7; ← else $z = 0; But to actually use code blocks, you do have to write {…} them as such! Even seasoned programmers avoid this braceless syntax, or at least understand it as an exceptional exception to the rule. Else / Elseif in wrong order One thing to remind yourself is the conditional order, of course. if ($a) { … } else { … } elseif ($b) { … } ↑ You can have as many elseifs as you want, but else has to go last. That's just how it is. Class declarations As mentioned above, you can't have control statements in a class declaration: class xyz { if (true) { function ($var) {} } You either forgot a function definition, or closed one } too early in such cases. Unexpected T_ELSEIF / T_ELSE When mixing PHP and HTML, the closing } for an if/elseif must be in the same PHP block <?php ?> as the next elseif/else. This will generate an error as the closing } for the if needs to be part of the elseif: <?php if ($x) { ?> html <?php } ?> <?php elseif ($y) { ?> html <?php } ?> The correct form <?php } elseif: <?php if ($x) { ?> html <?php } elseif ($y) { ?> html <?php } ?> This is more or less a variation of incorrect indentation - presumably often based on wrong coding intentions. You cannot mash other statements inbetween if and elseif/else structural tokens: if (true) { } echo "in between"; ← elseif (false) { } ?> text <?php ← else { } Either can only occur in {…} code blocks, not in between control structure tokens. This wouldn't make sense anyway. It's not like that there was some "undefined" state when PHP jumps between if and else branches. You'll have to make up your mind where print statements belong to / or if they need to be repeated in both branches. Nor can you part an if/else between different control structures: foreach ($array as $i) { if ($i) { … } } else { … } There is no syntactic relation between the if and else. The foreach lexical scope ends at }, so there's no point for the if structure to continue. T_ENDIF If an unexpected T_ENDIF is complained about, you're using the alternative syntax style if: ⋯ elseif: ⋯ else: ⋯ endif;. Which you should really think twice about. A common pitfall is confusing the eerily similar : colon for a ; semicolon. (Covered in "Semicolon too early") As indentation is harder to track in template files, the more when using the alternative syntax - it's plausible your endif; does not match any if:. Using } endif; is a doubled if-terminator. While an "unexpected $end" is usually the price for a forgotten closing } curly brace. Assignment vs. comparison So, this is not a syntax error, but worth mentioning in this context: ⇓ if ($x = true) { } else { do_false(); } That's not a ==/=== comparison, but an = assignment. This is rather subtle, and will easily lead some users to helplessly edit whole condition blocks. Watch out for unintended assignments first - whenver you experience a logic fault / misbeheviour.

意想不到的T_IS_EQUAL 意想不到的T_IS_GREATER_OR_EQUAL 意想不到的T_IS_IDENTICAL 意想不到的T_IS_NOT_EQUAL 意想不到的T_IS_NOT_IDENTICAL 意想不到的T_IS_SMALLER_OR_EQUAL 意想不到的< 意想不到的>

比较运算符，如==，>=，===，!=，<>，!==和<=或<和>，主要应该只在表达式中使用，例如if表达式。如果解析器抱怨它们，那么通常意味着它们周围的paren不正确或不匹配()。

Parens grouping In particular for if statements with multiple comparisons you must take care to correctly count opening and closing parenthesis: ⇓ if (($foo < 7) && $bar) > 5 || $baz < 9) { ... } ↑ Here the if condition here was already terminated by the ) Once your comparisons become sufficiently complex it often helps to split it up into multiple and nested if constructs rather. isset() mashed with comparing A common newcomer is pitfal is trying to combine isset() or empty() with comparisons: ⇓ if (empty($_POST["var"] == 1)) { Or even: ⇓ if (isset($variable !== "value")) { This doesn't make sense to PHP, because isset and empty are language constructs that only accept variable names. It doesn't make sense to compare the result either, because the output is only/already a boolean. Confusing >= greater-or-equal with => array operator Both operators look somewhat similar, so they sometimes get mixed up: ⇓ if ($var => 5) { ... } You only need to remember that this comparison operator is called "greater than or equal" to get it right. See also: If statement structure in PHP Nothing to compare against You also can't combine two comparisons if they pertain the same variable name: ⇓ if ($xyz > 5 and < 100) PHP can't deduce that you meant to compare the initial variable again. Expressions are usually paired according to operator precedence, so by the time the < is seen, there'd be only a boolean result left from the original variable. See also: unexpected T_IS_SMALLER_OR_EQUAL Comparison chains You can't compare against a variable with a row of operators: ⇓ $reult = (5 < $x < 10); This has to be broken up into two comparisons, each against $x. This is actually more a case of blacklisted expressions (due to equivalent operator associativity). It's syntactically valid in a few C-style languages, but PHP wouldn't interpret it as expected comparison chain either. Unexpected > Unexpected < The greater than > or less than < operators don't have a custom T_XXX tokenizer name. And while they can be misplaced like all they others, you more often see the parser complain about them for misquoted strings and mashed HTML: ⇓ print "<a href='z">Hello</a>"; ↑ This amounts to a string "<a href='z" being compared > to a literal constant Hello and then another < comparison. Or that's at least how PHP sees it. The actual cause and syntax mistake was the premature string " termination. It's also not possible to nest PHP start tags: <?php echo <?php my_func(); ?> ↑

参见:

php T_IS_NOT_EQUAL错误 语法错误，意外的T_IS_EQUAL 返回语句的语法错误 http://forums.phpfreaks.com/topic/96891-parse-error-syntax-error-unexpected-t-is-not-identical-expecting-or/