The numbers in the PHP path are not resolved to?

$file = "D:\PHP_OBJECT\6\2\param.txt"; echo $file;

is the number in the PHP path gone? , is Apache wrong or PHP set wrong, how to test it?

Reply to discussion (solution)

$file = ' D:\PHP_OBJECT\6\2\param.txt '; echo $file;

D:\PHP_OBJECT\6\2\param.txt
Double quotes will take effect, use with caution!

According to the rules, the characters \ should be escaped in double or single quotes.
$file = ' d:\\php_object\\6\\2\\param.txt ';

$file = ' D:\PHP_OBJECT\6\2\param.txt '; echo $file;

D:\PHP_OBJECT\6\2\param.txt
Double quotes will take effect, use with caution!

According to the rules, the characters \ should be escaped in double or single quotes.
$file = ' d:\\php_object\\6\\2\\param.txt ';

Thank you

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