a class btn bootstrap code example

Example 1: bootstrap button

<button type="button" class="btn btn-primary">Primary</button>
<button type="button" class="btn btn-secondary">Secondary</button>
<button type="button" class="btn btn-success">Success</button>
<button type="button" class="btn btn-danger">Danger</button>
<button type="button" class="btn btn-warning">Warning</button>
<button type="button" class="btn btn-info">Info</button>
<button type="button" class="btn btn-light">Light</button>
<button type="button" class="btn btn-dark">Dark</button>

<button type="button" class="btn btn-link">Link</button>

Example 2: bootstarp btn colors

<button type="button" class="btn btn-primary">Blue</button>
<button type="button" class="btn btn-secondary">Grey</button>
<button type="button" class="btn btn-success">Green</button>
<button type="button" class="btn btn-danger">Red</button>
<button type="button" class="btn btn-warning">Yellow</button>
<button type="button" class="btn btn-info">Ligth blue</button>
<button type="button" class="btn btn-light">White</button>
<button type="button" class="btn btn-dark">Black</button>

<button type="button" class="btn btn-link">White with blue text</button>

Example 3: button with sign in image bootstrap 4

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

<p class="mb-0">px-3:</p>
<a class="btn btn-lg px-3 btn-primary" href="#" role="button">USA <img src="https://lipis.github.io/flag-icon-css/flags/4x3/in.svg" height="30" alt="USA flag"></a>
<p class="mb-0">px-4:</p>
<a class="btn btn-lg px-4 btn-primary" href="#" role="button">USA <img src="https://lipis.github.io/flag-icon-css/flags/4x3/in.svg" height="30" alt="USA flag"></a>
<p class="mb-0">px-5:</p>
<a class="btn btn-lg px-5 btn-primary" href="#" role="button">USA <img src="https://lipis.github.io/flag-icon-css/flags/4x3/in.svg" height="30" alt="USA flag"></a>