author-bio.php

<?php
/**
 * Author description.
 */

if ( get_the_author_meta( 'description' ) ) :
	?>
<div class="author-info">
	<h2>
		<?php
			echo get_avatar( get_the_author_meta( 'user_email' ), apply_filters( 'themes_starter_author_bio_avatar_size', 48 ) ) . '&nbsp;';
			printf( esc_html__( 'About %s', 'my-theme' ), get_the_author() );
		?>
	</h2>
	<p class="author-description">
		<?php the_author_meta( 'description' ); ?>
	</p>
	<p class="author-links">
		<?php
		if ( ! empty( get_the_author_meta( 'user_url' ) ) ) {
			printf( '<a href="%s" class="www mdc-button mdc-js-button">' . esc_html__( 'Website', 'my-theme' ) . '</a>', esc_url( get_the_author_meta( 'user_url' ) ) );
		}

			// Add new Profile fields for Users in functions.php
			$fields = array(
				array(
					'meta'  => 'facebook_profile',
					'label' => 'Facebook',
				),
				array(
					'meta'  => 'twitter_profile',
					'label' => 'Twitter',
				),
				array(
					'meta'  => 'linkedin_profile',
					'label' => 'LinkedIn',
				),
				array(
					'meta'  => 'xing_profile',
					'label' => 'Xing',
				),
				array(
					'meta'  => 'github_profile',
					'label' => 'GitHub',
				),
			);

			foreach ( $fields as $key => $data ) {
				$author_link = get_the_author_meta( esc_attr( $data['meta'] ) );
				if ( ! empty( $author_link ) ) {
					$label = $data['label'];
					echo ' <a href="' . esc_url( $author_link ) . '" class="mdc-button mdc-js-button" title="' . esc_attr( $label ) . '">' . esc_html( $label ) . '</a> ';
				}
			}
			?>
	</p>
</div><!-- /.author-info -->
	<?php
	endif;
?>