意想不到的:

1. PHP 8命名参数语法

Unexpected ':'， expected '，' or ')'

如果试图在PHP < 8的版本中使用PHP 8的新命名形参功能，将会出现以下错误:

$table->string(column:'Name');

解决方案:

将PHP版本升级到PHP 8.0.0或更高版本 不要使用命名参数(按照预期的顺序传递参数)

2. 裁剪类::分隔符

以“解析错误:语法错误，意外的‘:’”开头的错误消息可能是由于错误地将类静态引用class::$Variable写成class:$Variable而引起的。

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();)。

意想不到的T_STRING

T_STRING有点用词不当。它不引用引用的“字符串”。这意味着遇到了原始标识符。这可以是空白的单词、剩余的CONSTANT或函数名、被遗忘的不带引号的字符串或任何纯文本。

Misquoted strings This syntax error is most common for misquoted string values however. Any unescaped and stray " or ' quote will form an invalid expression: ⇓ ⇓ echo "<a href="http://example.com">click here</a>"; Syntax highlighting will make such mistakes super obvious. It's important to remember to use backslashes for escaping \" double quotes, or \' 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 " double quotes. For lengthier output, prefer multiple echo/print 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: $text = '<div>some text with <?php echo 'some php entry' ?></div>' This happens if $text 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?. 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: ⇓ echo "Some text", $a_variable, "and some runaway string ; success("finished"); ⇯ It's not just literal T_STRINGs which the parser may protest then. Another frequent variation is an Unexpected '>' for unquoted literal HTML. 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't what PHP expects: $text = ’Something something..’ + ”these ain't quotes”; Typographic/smart quotes are Unicode symbols. PHP treats them as part of adjoining alphanumeric text. For example ”these is interpreted as a constant identifier. But any following text literal is then seen as a bareword/T_STRING by the parser. The missing semicolon; again If you have an unterminated expression in previous lines, then any following statement or language construct gets seen as raw identifier: ⇓ func1() function2(); PHP just can'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 || or the other. Short open tags and <?xml headers in PHP scripts This is rather uncommon. But if short_open_tags are enabled, then you can't begin your PHP scripts with an XML declaration: ⇓ <?xml version="1.0"?> PHP will see the <? and reclaim it for itself. It won't understand what the stray xml was meant for. It'll get interpreted as constant. But the version will be seen as another literal/constant. And since the parser can't make sense of two subsequent literals/values without an expression operator in between, that'll be a parser failure. Invisible Unicode characters A most hideous cause for syntax errors are Unicode symbols, such as the non-breaking space. PHP allows Unicode characters as identifier names. If you get a T_STRING parser complaint for wholly unsuspicious code like: <?php print 123; You need to break out another text editor. Or an hexeditor even. What looks like plain spaces and newlines here, may contain invisible constants. Java-based IDEs are sometimes oblivious to an UTF-8 BOM mangled within, zero-width spaces, paragraph separators, etc. Try to reedit everything, remove whitespace and add normal spaces back in. You can narrow it down with with adding redundant ; statement separators at each line start: <?php ;print 123; The extra ; semicolon here will convert the preceding invisible character into an undefined constant reference (expression as statement). Which in return makes PHP produce a helpful notice. The `$` sign missing in front of variable names Variables in PHP are represented by a dollar sign followed by the name of the variable. The dollar sign ($) is a sigil that marks the identifier as a name of a variable. Without this sigil, the identifier could be a language keyword or a constant. This is a common error when the PHP code was "translated" from code written in another language (C, Java, JavaScript, etc.). In such cases, a declaration of the variable type (when the original code was written in a language that uses typed variables) could also sneak out and produce this error. Escaped Quotation marks If you use \ in a string, it has a special meaning. This is called an "Escape Character" and normally tells the parser to take the next character literally. Example: echo 'Jim said \'Hello\''; will print Jim said 'hello' If you escape the closing quote of a string, the closing quote will be taken literally and not as intended, i.e. as a printable quote as part of the string and not close the string. This will show as a parse error commonly after you open the next string or at the end of the script. Very common error when specifiying paths in Windows: "C:\xampp\htdocs\" is wrong. You need "C:\\xampp\\htdocs\\". Typed properties You need PHP ≥7.4 to use property typing such as: public stdClass $obj;

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_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 {

意想不到的T_VARIABLE

一个“意外的T_VARIABLE”意味着有一个字面的$变量名，它不适合当前表达式/语句结构。

Missing semicolon It most commonly indicates a missing semicolon in the previous line. Variable assignments following a statement are a good indicator where to look: ⇓ func1() $var = 1 + 2; # parse error in line +2 String concatenation A frequent mishap are string concatenations with forgotten . operator: ⇓ print "Here comes the value: " $value; Btw, you should prefer string interpolation (basic variables in double quotes) whenever that helps readability. Which avoids these syntax issues. String interpolation is a scripting language core feature. No shame in utilizing it. Ignore any micro-optimization advise about variable . concatenation being faster. It's not. Missing expression operators Of course the same issue can arise in other expressions, for instance arithmetic operations: ⇓ print 4 + 7 $var; PHP can't guess here if the variable should have been added, subtracted or compared etc. Lists Same for syntax lists, like in array populations, where the parser also indicates an expected comma , for example: ⇓ $var = array("1" => $val, $val2, $val3 $val4); Or functions parameter lists: ⇓ function myfunc($param1, $param2 $param3, $param4) Equivalently do you see this with list or global statements, or when lacking a ; semicolon in a for loop. Class declarations This parser error also occurs in class declarations. You can only assign static constants, not expressions. Thus the parser complains about variables as assigned data: class xyz { ⇓ var $value = $_GET["input"]; Unmatched } closing curly braces can in particular lead here. If a method is terminated too early (use proper indentation!), then a stray variable is commonly misplaced into the class declaration body. Variables after identifiers You can also never have a variable follow an identifier directly: ⇓ $this->myFunc$VAR(); Btw, this is a common example where the intention was to use variable variables perhaps. In this case a variable property lookup with $this->{"myFunc$VAR"}(); for example. Take in mind that using variable variables should be the exception. Newcomers often try to use them too casually, even when arrays would be simpler and more appropriate. Missing parentheses after language constructs Hasty typing may lead to forgotten opening or closing parenthesis for if and for and foreach statements: ⇓ foreach $array as $key) { Solution: add the missing opening ( between statement and variable. ⇓ if ($var = pdo_query($sql) { $result = … The curly { brace does not open the code block, without closing the if expression with the ) closing parenthesis first. Else does not expect conditions ⇓ else ($var >= 0) Solution: Remove the conditions from else or use elseif. Need brackets for closure ⇓ function() use $var {} Solution: Add brackets around $var. Invisible whitespace As mentioned in the reference answer on "Invisible stray Unicode" (such as a non-breaking space), you might also see this error for unsuspecting code like: <?php ⇐ $var = new PDO(...); It's rather prevalent in the start of files and for copy-and-pasted code. Check with a hexeditor, if your code does not visually appear to contain a syntax issue.

另请参阅

搜索:意外T_VARIABLE