转义序列不正确

Question

I have a pattern that I want to match, but the compiler says that it is incorrect. How should I correct make the scape sequence in java?

This is the pattern:

String patter = "\/\/s.ytimg.com\/yts\/jsbin\/html5player-en_US-vfllxLx6Z\/html5player.js"

Answer 1

The compiler complains because there is no such escape character as \\/ . Common escape characters are these:

• \\n newline
• \\t tab
• ...

To embed a literal \\ in a string, you need to use \\\\ , for example:

String pattern = "\\/\\/s.ytimg.com\\/yts\\/jsbin\\/html5player-en_US-vfllxLx6Z\\/html5player.js";

But actually, I don't really see why you need \\ there at all. I think what you really need is most probably no \\ at all:

String pattern = "//s.ytimg.com/yts/jsbin/html5player-en_US-vfllxLx6Z/html5player.js";

Answer 2

If you want to escape \\ then you need to make it double like \\\\ . You may try this:

String patter = "\\/\\/s.ytimg.com\\/yts\\/jsbin\\/html5player-en_US-vfllxLx6Z\\/html5player.js";

Answer 3

In any case where \\ is used, it needs to be duplicated, as \\ is used to escape special sequences, for example \\n to create a newline. \\\\ is equivalent to a single \\ in the actual url.

For your actual URL, use this:

String patter = "\\/\\/s.ytimg.com\\/yts\\/jsbin\\/html5player-en_US-vfllxLx6Z\\/html5player.js"

However, if you were trying to escape the / character, that is unnecessary. You can just use this:

String patter = "//s.ytimg.com/yts/jsbin/html5player-en_US-vfllxLx6Z/html5player.js"