A Solution to `syntax error, unexpected $end` in PHP

When PHP encounters the error syntax error, unexpected $end, the debugging steps are as follows:

1. Check whether the PHP opening tag <?php and closing tag ?> are properly paired in the file.
2. Pay extra attention to whether ?> appears within comments.

Error example:

Parse error: syntax error, unexpected $end in script.php on line xx

After debugging, it was found that the error occurred in the middle of the file on the following line:

//$str .= "?>\n";

Problem Analysis

The PHP interpreter allows single-line comments before the closing tag. For example:

//$str .= "?>\n";

This is interpreted as:

• A comment before the closing tag, with the content `//$str .= ".
• The ?> and the subsequent \n"; are interpreted as content outside the PHP block and output as HTML.

As a result, adding // to $str .= "?>\n"; to make it a comment inadvertently introduces an extra ?> closing tag, causing the original valid closing tag to become unexpected (unexpected).

Solution

• Directly delete the problematic line:

//$str .= "?>\n";

• Follow good coding practices:

• Do not write other content on the same line as PHP opening and closing tags.

• Modify the php.ini configuration:

• Set short_open_tag = On.