CSS 属性值中的波浪号

Question

I found some CSS like this:

margin-top: ~"-2px\9";

Can anyone tell me what it is and what it does?

Answer 1

What is it?

A syntax error.

What does it do?

Breaks your stylesheet.

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As mentioned in the comments on your question, it may be LESS instead of CSS. In LESS, a tilde before a string literal outputs the string as-is, because it may be a syntax error in pure LESS. \\9 is an IE hack . See Escaping .

Answer 2

It may be a LESS Syntax. But tilde character is used in CSS3 as well. Eg the below Syntax:

p ~ ul { background:#ff0; }

will target ul elements that are preceded by ap element with the same parent:

Answer 3

In Less, this is called "Escaping" .

Escaping allows you to use any random string as a property value or variable value.

For example ~"value" or ~'value' will be used as is without changes being made, only exception is interpolation.

Link to Less Docs: http://lesscss.org/#escaping