每个人都会遇到语法错误。即使是经验丰富的程序员也会出现拼写错误。对于新人来说,这只是学习过程的一部分。然而,通常很容易解释如下错误消息:
PHP解析错误:语法错误,在index.php第20行中出现意外的“{”
意想不到的符号并不总是真正的罪魁祸首。但是行号给出了从哪里开始查找的大致概念。
总是查看代码上下文。语法错误通常隐藏在前面提到的或前面的代码行中。将您的代码与手册中的语法示例进行比较。
但并不是所有情况都是一样的。但是有一些通用的步骤可以解决语法错误。
本文总结了常见的陷阱:
Unexpected T_STRING
Unexpected T_VARIABLE Unexpected '$varname' (T_VARIABLE)
Unexpected T_CONSTANT_ENCAPSED_STRING Unexpected T_ENCAPSED_AND_WHITESPACE
Unexpected $end
Unexpected T_FUNCTION…
Unexpected {Unexpected }Unexpected (Unexpected )
Unexpected [Unexpected ]
Unexpected T_IF Unexpected T_FOREACH Unexpected T_FOR Unexpected T_WHILE Unexpected T_DO Unexpected T_PRINT Unexpected T_ECHO
Unexpected T_LNUMBER
Unexpected ?
Unexpected continue (T_CONTINUE)Unexpected continue (T_BREAK)Unexpected continue (T_RETURN)
Unexpected '='
Unexpected T_INLINE_HTML…
Unexpected T_PAAMAYIM_NEKUDOTAYIM…
Unexpected T_OBJECT_OPERATOR…
Unexpected T_DOUBLE_ARROW…
Unexpected T_SL…
Unexpected T_BOOLEAN_OR…
Unexpected T_BOOLEAN_AND…
Unexpected T_IS_EQUAL
Unexpected T_IS_GREATER_OR_EQUAL
Unexpected T_IS_IDENTICAL
Unexpected T_IS_NOT_EQUAL
Unexpected T_IS_NOT_IDENTICAL
Unexpected T_IS_SMALLER_OR_EQUAL
Unexpected <
Unexpected >
Unexpected T_NS_SEPARATOR…
Unexpected character in input: '\' (ASCII=92) state=1
Unexpected 'public' (T_PUBLIC) Unexpected 'private' (T_PRIVATE) Unexpected 'protected' (T_PROTECTED) Unexpected 'final' (T_FINAL)…
Unexpected T_STATIC…
Unexpected T_CLASS…
Unexpected 'use' (T_USE)
Unexpected T_DNUMBER
Unexpected , (comma)
Unpexected . (period)
Unexpected ; (semicolon)
Unexpected * (asterisk)
Unexpected : (colon)
Unexpected ':', expecting ',' or ')'
Unexpected & (call-time pass-by-reference)
Unexpected .
密切相关的参考文献:
这个错误在PHP中意味着什么?(运行时错误)
解析错误:语法错误,意外的T_XXX
解析错误:语法错误,意外的T_ENCAPSED_AND_WHITESPACE
解析错误:语法错误,意外的T_VARIABLE
这个符号在PHP中是什么意思?(语言标记)
这些“聪明”的引号对PHP毫无意义
And:
php.net上的PHP手册和它的各种语言标记
或者维基百科关于PHP的语法介绍。
最后是我们的php标签维基。
虽然Stack Overflow也欢迎新手程序员,但它主要针对的是专业编程问题。
回答每个人的编码错误和狭窄的拼写错误被认为是离题了。
因此,在发布语法修正请求之前,请花时间遵循基本步骤。
如果你仍然必须这样做,请展示你自己的解决方案,尝试修复,以及你对看起来或可能错误的思考过程。
如果您的浏览器显示错误消息,如“SyntaxError: illegal character”,那么它实际上不是php相关的,而是javascript语法错误。
供应商代码引起的语法错误:最后,考虑一下,如果语法错误不是由编辑代码库引起的,而是在外部供应商包安装或升级之后引起的,则可能是由于PHP版本不兼容造成的,因此请根据平台设置检查供应商的要求。
意想不到的(
现在,在过时的PHP版本中经常可以看到意外的[array括号]。短数组语法从PHP >= 5.4开始可用。旧的安装只支持array()。
$php53 = array(1, 2, 3);
$php54 = [1, 2, 3];
⇑
数组函数结果解引用同样不适用于旧的PHP版本:
$result = get_whatever()["key"];
⇑
这个错误在PHP中意味着什么?-“语法错误,意外的\[”显示了最常见和实用的解决方案。
不过,最好还是升级PHP安装。对于共享网络托管计划,首先要研究是否可以使用SetHandler php5 56-fcgi来启用新的运行时。
参见:
对函数result→进行解引用的PHP语法,从PHP 5.4开始可能
PHP语法错误,意外的“[”
数组的简写:是否存在像{}或[]这样的文字语法?
PHP 5.3.10 vs PHP 5.5.3语法错误
数组()和[]的区别
PHP数组语法解析错误
顺便说一下,如果你对老版本和慢版本的PHP很感兴趣的话,还有预处理器和PHP 5.4语法下转换器。
导致意外语法错误的其他原因
如果不是PHP版本不匹配,那么通常是一个简单的拼写错误或新手语法错误:
You can't use array property declarations/expressions in classes, not even in PHP 7.
protected $var["x"] = "Nope";
⇑
Confusing [ with opening curly braces { or parentheses ( is a common oversight.
foreach [$a as $b)
⇑
Or even:
function foobar[$a, $b, $c] {
⇑
Or trying to dereference constants (before PHP 5.6) as arrays:
$var = const[123];
⇑
At least PHP interprets that const as a constant name.
If you meant to access an array variable (which is the typical cause here), then add the leading $ sigil - so it becomes a $varname.
You are trying to use the global keyword on a member of an associative array. This is not valid syntax:
global $var['key'];
结束方括号
这种情况比较少见,但是终止数组[括号]也会出现语法错误。
同样,与)括号或}大括号不匹配是常见的:
函数foobar($a, $b, $c] {
⇑
或者试图结束一个没有数组的数组:
$var = 2];
这通常发生在多行和嵌套数组声明中。
$数组=[1,2,3],4(5、6 (7 [8][9 10]],11),12]],15);
⇑
如果是,请使用IDE进行括号匹配以查找任何过早的]数组闭包。至少使用更多的空格和换行来缩小范围。
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 {
One more reason to occurrence of these errors is unexpected whitespace like similar characters with-in code, the code lines seems to be perfect, but they contains some specific characters which are similar to break line or whitespace or tab but they not get parsed by the parser.
I face this issue when I try to put some code from webpage to the code editor by simply copy paste, I saw this error with array definition. everything was looking right in array definition. I can't sort out right error, finally I define this array in single line, then error was gone. then again I try to make that definition multiple like but manually adding break(Enter) for each array element and saved the file this time no parsing error by editor and also no error while running it.
For Example I faced issue with this snippet which was on one blog, actually can't post those snippets ,cause stack overflow already knows the problem with code.
然后在解决它之后,我的工作片段是,它看起来类似于一个显示解析错误
语法错误,意外的“auth”(T_CONSTANT_ENCAPSED_STRING),期待']'
public $aliases = [
'csrf'=> \CodeIgniter\Filters\CSRF::class,
'toolbar'=> \CodeIgniter\Filters\DebugToolbar::class,
'honeypot'=> \CodeIgniter\Filters\Honeypot::class,
'auth' => \App\Filters\Auth::class,
];
意想不到的T_VARIABLE
一个“意外的T_VARIABLE”意味着有一个字面的$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
意想不到的T_LNUMBER
令牌T_LNUMBER指向一个“长”/ number。
Invalid variable names
In PHP, and most other programming languages, variables cannot start with a number. The first character must be alphabetic or an underscore.
$1 // Bad
$_1 // Good
Quite often comes up for using preg_replace-placeholders "$1" in PHP context:
# ↓ ⇓ ↓
preg_replace("/#(\w+)/e", strtopupper($1) )
Where the callback should have been quoted. (Now the /e regex flag has been deprecated. But it's sometimes still misused in preg_replace_callback functions.)
The same identifier constraint applies to object properties, btw.
↓
$json->0->value
While the tokenizer/parser does not allow a literal $1 as variable name, one could use ${1} or ${"1"}. Which is a syntactic workaround for non-standard identifiers. (It's best to think of it as a local scope lookup. But generally: prefer plain arrays for such cases!)
Amusingly, but very much not recommended, PHPs parser allows Unicode-identifiers; such that $➊ would be valid. (Unlike a literal 1).
Stray array entry
An unexpected long can also occur for array declarations - when missing , commas:
# ↓ ↓
$xy = array(1 2 3);
Or likewise function calls and declarations, and other constructs:
func(1, 2 3);
function xy($z 2);
for ($i=2 3<$z)
So usually there's one of ; or , missing for separating lists or expressions.
Misquoted HTML
And again, misquoted strings are a frequent source of stray numbers:
# ↓ ↓
echo "<td colspan="3">something bad</td>";
Such cases should be treated more or less like Unexpected T_STRING errors.
Other identifiers
Neither functions, classes, nor namespaces can be named beginning with a number either:
↓
function 123shop() {
Pretty much the same as for variable names.