FreeCodeCamp - BootStrap Icons

Font Awesome is a convenient library of icons. These icons are vector graphics, stored in the .svg file format. These icons are treated just like fonts. You can specify their size using pixels, and they will assume the font size of their parent HTML elements. You can add Font Awesome to any app just by including it by adding the following code to the top of your HTML:

<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css"/> In this case, we've already added it for you to this page behind the scenes.

The i element was originally used to make other elements italic, but is now commonly used for icons. You add the Font Awesome classes to the i element to turn it into an icon, for example:

<i class="fa fa-info-circle"></i>

Use Font Awesome to add a thumbs-up icon to your like button by giving it an i element with the classes fa and fa-thumbs-up. fa-circle fa-trash are the same.

 <i class="fa fa-thumbs-up"></i>
 <i class="fa fa-circle"></i>
 <i class="fa fa-trash"></i>

You can add the fa-paper-plane Font Awesome icon by adding <i class="fa fa-paper-plane"></i> within your submit button element.

<button type="submit" class="btn btn-primary"><i class="fa fa-paper-plane"></i>Submit</button>

Give your form's text input field a class of form-control

<input class="form-control" type="text" placeholder="cat photo URL" required>

转载于:https://my.oschina.net/u/1273644/blog/857184