Single-line comments (//) and perl-style comments (#!) are not allowed in PHP. Therefore, these two annotation methods cannot be used in PHP.
Comment methods that cannot be used in PHP
Two comment methods are not allowed in PHP:
1. Single-line comments (//)
In PHP, single-line comments start with double slashes (//). However, the PHP interpreter treats // as a line separator, not a comment separator. Therefore, single-line comments cannot be used in PHP.
2. Perl-style comments (#!)
In Perl, perl-style comments start with #!. This kind of comment has special meaning to the Perl interpreter, but not in PHP. Therefore, perl-style comments cannot be used in PHP.
For example:
The following code is not valid in PHP because it attempts to use a single line comment:
<code>// 这是一个单行注释</code>
The following code is also invalid in PHP, Because it tries to use perl-style comments:
<code>#! 这是一个perl 式注释</code>
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