What Is The ::before Or ::after Expression, And Why Is It Shown In The Browser Developer Tools?

I have read ::before is used to add content before the element you use it with, e.g. p::before { content: 'Read this: '; } but most of the times I have seen (peeking at web p

Solution 1:

CSS-Tricks:

CSS has a property called content. It can only be used with the pseudo elements :after and :before. It is written like a pseudo selector (with the colon), but it's called a pseudo element because it's not actually selecting anything that exists on the page but adding something new to the page.

::before insert content before an element using css.

q::before { 
  content: "«";
  color: blue;
}

::after insert content after an element.

q::after { 
  content: "»";
  color: red;
}

Demo

you can use Special Characters too, some of them:

\2018 - Left Single Smart Quote

\2019 - Right Single Smart Quote

\00A9 - Copyright

\2713 - Checkmark

\2192 - Right arrow

\2190 - Left arrow

you can use element attributes too:

<a title="A web design community." href="http://css-tricks.com">CSS-Tricks</a>

a:before {
   content: attr(title) ": ";
}

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