当你在PHP中对empty()函数应用常量时，也会出现这种情况:

if (!empty(SOME_CONSTANT)) {

}

那是我的案子。我用这个方法解决了这个问题:

$string = SOME_CONSTANT;
if (!empty($string)) {

}

从维基百科:

In PHP, the scope resolution operator is also called Paamayim Nekudotayim (Hebrew: פעמיים נקודתיים‎), which means “double colon” in Hebrew. The name "Paamayim Nekudotayim" was introduced in the Israeli-developed Zend Engine 0.5 used in PHP 3. Although it has been confusing to many developers who do not speak Hebrew, it is still being used in PHP 5, as in this sample error message: $ php -r :: Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM As of PHP 5.4, error messages concerning the scope resolution operator still include this name, but have clarified its meaning somewhat: $ php -r :: Parse error: syntax error, unexpected '::' (T_PAAMAYIM_NEKUDOTAYIM)

来自PHP官方文档:

The Scope Resolution Operator (also called Paamayim Nekudotayim) or in simpler terms, the double colon, is a token that allows access to static, constant, and overridden properties or methods of a class. When referencing these items from outside the class definition, use the name of the class. As of PHP 5.3.0, it's possible to reference the class using a variable. The variable's value can not be a keyword (e.g. self, parent and static). Paamayim Nekudotayim would, at first, seem like a strange choice for naming a double-colon. However, while writing the Zend Engine 0.5 (which powers PHP 3), that's what the Zend team decided to call it. It actually does mean double-colon - in Hebrew!

希伯来语是"双冒号"的意思。

这可能发生在foreach时使用:

foreach( $array as $key = $value )

而不是

foreach( $array as $key => $value )

它是双冒号操作符::(参见解析器令牌列表)。

当你在PHP中对empty()函数应用常量时，也会出现这种情况:

if (!empty(SOME_CONSTANT)) {

}

那是我的案子。我用这个方法解决了这个问题:

$string = SOME_CONSTANT;
if (!empty($string)) {

}