为什么在PHP中print'\\ n'和print'\\\\ n'显示相同的输出？

Question

<?php
print '\n';
print '\\n';
?>

For the above php code, i got output the following output:( http://ideone.com/vKRtgb )

\n\n

So, what is the difference between print'\\n' and print'\\\\n' ? I know that singly quoted strings are treated literally, but I expected the output to be \\n\\\\n instead of \\n\\n

Answer 1

Because in single-quoted strings in PHP can only escape single quotes and backslashes. Use double-quoted strings for escaping other characters like \\n .

From the PHP documentation linked above:

To specify a literal single quote, escape it with a backslash (\\). To specify a literal backslash, double it (\\\\). All other instances of backslash will be treated as a literal backslash: this means that the other escape sequences you might be used to, such as \\r or \\n, will be output literally as specified rather than having any special meaning .

Answer 2

当使用双引号（“）时，PHP仅解释转义字符（转义反斜杠\\和转义单引号\\'除外）