WordPress Breadcrumbs Function with Boostrap Support.

breadcrumbs.php

<?php

/**
 * Display breadcrumbs.
 * 
 * @since  1.0.0.
 * @param  array  $args
 * @return string $html
 */
function anva_get_breadcrumbs( $args = array() ) {

	if ( is_front_page() ) {
		return;
	}

	global $post;

	$defaults  = array(
		'separator_icon'      => '/',
		'breadcrumbs_id'      => 'breadcrumb',
		'breadcrumbs_classes' => 'breadcrumb-trail breadcrumb',
		'home_title'          => __( 'Home', 'anva' )
	);

	$args      = apply_filters( 'anva_get_breadcrumbs_args', wp_parse_args( $args, $defaults ) );
	$separator = '<li class="separator"> ' . esc_attr( $args['separator_icon'] ) . ' </li>';
	

	// Open the breadcrumbs
	$html = '<ol id="' . esc_attr( $args['breadcrumbs_id'] ) . '" class="' . esc_attr( $args['breadcrumbs_classes'] ) . '">';
	
	// Add Homepage link & separator (always present)
	$html .= '<li class="item-home"><a class="bread-link bread-home" href="' . get_home_url() . '" title="' . esc_attr( $args['home_title'] ) . '">' . esc_attr( $args['home_title'] ) . '</a></li>';
	$html .= $separator;
	
	// Post
	if ( is_singular( 'post' ) ) {
		
		$category = get_the_category();
		$category_values = array_values( $category );
		$last_category = end( $category_values );
		$cat_parents = rtrim( get_category_parents( $last_category->term_id, true, ',' ), ',' );
		$cat_parents = explode( ',', $cat_parents );

		foreach ( $cat_parents as $parent ) {
			$html .= '<li class="item-cat">' . wp_kses( $parent, wp_kses_allowed_html( 'a' ) ) . '</li>';
			$html .= $separator;
		}

		$html .= '<li class="item-current item-' . $post->ID . '"><span class="bread-current bread-' . $post->ID . '" title="' . get_the_title() . '">' . get_the_title() . '</span></li>';
	
	} elseif ( is_singular( 'page' ) ) {

		if ( $post->post_parent ) {

			$parents = get_post_ancestors( $post->ID );
			$parents = array_reverse( $parents );

			foreach ( $parents as $parent ) {
				$html .= '<li class="item-parent item-parent-' . esc_attr( $parent ) . '"><a class="bread-parent bread-parent-' . esc_attr( $parent ) . '" href="' . esc_url( get_permalink( $parent ) ) . '" title="' . get_the_title( $parent ) . '">' . get_the_title( $parent ) . '</a></li>';
				$html .= $separator;
			}

		}

		$html .= '<li class="item-current item-' . $post->ID . '"><span title="' . get_the_title() . '"> ' . get_the_title() . '</span></li>';

	} elseif ( is_singular( 'attachment' ) ) {

		$parent_id        = $post->post_parent;
		$parent_title     = get_the_title( $parent_id );
		$parent_permalink = esc_url( get_permalink( $parent_id ) );
		
		$html .= '<li class="item-parent"><a class="bread-parent" href="' . esc_url( $parent_permalink ) . '" title="' . esc_attr( $parent_title ) . '">' . esc_attr( $parent_title ) . '</a></li>';
		$html .= $separator;
		$html .= '<li class="item-current item-' . $post->ID . '"><span title="' . get_the_title() . '"> ' . get_the_title() . '</span></li>';

	} elseif ( is_singular() ) {

		$post_type         = get_post_type();
		$post_type_object  = get_post_type_object( $post_type );
		$post_type_archive = get_post_type_archive_link( $post_type );

		$html .= '<li class="item-cat item-custom-post-type-' . esc_attr( $post_type ) . '"><a class="bread-cat bread-custom-post-type-' . esc_attr( $post_type ) . '" href="' . esc_url( $post_type_archive ) . '" title="' . esc_attr( $post_type_object->labels->name ) . '">' . esc_attr( $post_type_object->labels->name ) . '</a></li>';

		$html .= $separator;

		$html .= 'li class="item-current item-' . $post->ID . '"><span class="bread-current bread-' . $post->ID . '" title="' . $post->post_title . '">' . $post->post_title . '</span></li>';

	} elseif ( is_category() ) {

		$parent = get_queried_object()->category_parent;

		if ( $parent !== 0 ) {

			$parent_category = get_category( $parent );
			$category_link   = get_category_link( $parent );
			$html .= '<li class="item-parent item-parent-' . esc_attr( $parent_category->slug ) . '"><a class="bread-parent bread-parent-' . esc_attr( $parent_category->slug ) . '" href="' . esc_url( $category_link ) . '" title="' . esc_attr( $parent_category->name ) . '">' . esc_attr( $parent_category->name ) . '</a></li>';
			$html .= $separator;

		}
		
		$html .= '<li class="item-current item-cat"><span class="bread-current bread-cat" title="' . $post->ID . '">' . single_cat_title( '', false ) . '</span></li>';

	} elseif ( is_tag() ) {
		$html .= '<li class="item-current item-tag"><span class="bread-current bread-tag">' . single_tag_title( '', false ) . '</span></li>';

	} elseif ( is_author() ) {
		$html .= '<li class="item-current item-author"><span class="bread-current bread-author">' . get_queried_object()->display_name . '</span></li>';

	} elseif ( is_day() ) {
		$html .= '<li class="item-current item-day"><span class="bread-current bread-day">' . get_the_date() . '</span></li>';

	} elseif ( is_month() ) {
		$html .= '<li class="item-current item-month"><span class="bread-current bread-month">' . get_the_date( 'F Y' ) . '</span></li>';

	} elseif ( is_year() ) {
		$html .= '<li class="item-current item-year"><span class="bread-current bread-year">' . get_the_date( 'Y' ) . '</span></li>';

	} elseif ( is_archive() ) {
		$custom_tax_name = get_queried_object()->name;
		$html .= '<li class="item-current item-archive"><span class="bread-current bread-archive">' . esc_attr( $custom_tax_name ) . '</span></li>';

	} elseif ( is_search() ) {
		$html .= '<sliclass="item-current item-search"><span class="bread-current bread-search">Search results for: ' . get_search_query() . '</span></li>';

	} elseif ( is_404() ) {
		$html .= '<li>' . __( 'Error 404', 'ignite' ) . '</li>';

	} elseif ( is_home() ) {
		$html .= '<li>' . get_the_title( get_option( 'page_for_posts' ) ) . '</li>';
	}

	$html .= '</ol>';
	
	$html = apply_filters( 'anva_get_breadcrumbs', $html );
	
	echo wp_kses_post( $html );
}

Add this line to your css file.

.breadcrumb .separator { display: none; }

To match with bootstrap separator.