It gets really kind of trippy if you wanna output a backslash, \ you can't just use the backslash, \\ you need to use backslash backslash because otherwise a single backslash is confused with the so called escape character.

如果你想输出一个反斜杠，估计又得迷糊了，实际上，你不能直接用，而是要,否则一个\可能会被误认为,是转义字符。

哈佛公开课 - 计算机科学课程节选

So, when in doubt, if you're having some weird character issue, odds are you need to escape it in some way.

如果你有拿不准的字符,可能就要用到转义字符了。

哈佛公开课 - 计算机科学课程节选