diff --git a/src/wp-includes/class-wp-comment-query.php b/src/wp-includes/class-wp-comment-query.php
index 6a72c0d209d5b..40e133e2d0311 100644
--- a/src/wp-includes/class-wp-comment-query.php
+++ b/src/wp-includes/class-wp-comment-query.php
@@ -941,12 +941,12 @@ protected function get_comment_ids() {
 		 */
 		$clauses = apply_filters_ref_array( 'comments_clauses', array( compact( $pieces ), &$this ) );
 
-		$fields  = isset( $clauses['fields'] ) ? $clauses['fields'] : '';
-		$join    = isset( $clauses['join'] ) ? $clauses['join'] : '';
-		$where   = isset( $clauses['where'] ) ? $clauses['where'] : '';
-		$orderby = isset( $clauses['orderby'] ) ? $clauses['orderby'] : '';
-		$limits  = isset( $clauses['limits'] ) ? $clauses['limits'] : '';
-		$groupby = isset( $clauses['groupby'] ) ? $clauses['groupby'] : '';
+		$fields  = $clauses['fields'] ?? '';
+		$join    = $clauses['join'] ?? '';
+		$where   = $clauses['where'] ?? '';
+		$orderby = $clauses['orderby'] ?? '';
+		$limits  = $clauses['limits'] ?? '';
+		$groupby = $clauses['groupby'] ?? '';
 
 		$this->filtered_where_clause = $where;
 
diff --git a/src/wp-includes/class-wp-customize-manager.php b/src/wp-includes/class-wp-customize-manager.php
index 51c88ef5fcf81..4d9f9a8f1ec56 100644
--- a/src/wp-includes/class-wp-customize-manager.php
+++ b/src/wp-includes/class-wp-customize-manager.php
@@ -1226,9 +1226,9 @@ public function import_theme_starter_content( $starter_content = array() ) {
 		$sidebars_widgets = isset( $starter_content['widgets'] ) && ! empty( $this->widgets ) ? $starter_content['widgets'] : array();
 		$attachments      = isset( $starter_content['attachments'] ) && ! empty( $this->nav_menus ) ? $starter_content['attachments'] : array();
 		$posts            = isset( $starter_content['posts'] ) && ! empty( $this->nav_menus ) ? $starter_content['posts'] : array();
-		$options          = isset( $starter_content['options'] ) ? $starter_content['options'] : array();
+		$options          = $starter_content['options'] ?? array();
 		$nav_menus        = isset( $starter_content['nav_menus'] ) && ! empty( $this->nav_menus ) ? $starter_content['nav_menus'] : array();
-		$theme_mods       = isset( $starter_content['theme_mods'] ) ? $starter_content['theme_mods'] : array();
+		$theme_mods       = $starter_content['theme_mods'] ?? array();
 
 		// Widgets.
 		$max_widget_numbers = array();
@@ -1495,7 +1495,7 @@ public function import_theme_starter_content( $starter_content = array() ) {
 			$this->set_post_value(
 				$nav_menu_setting_id,
 				array(
-					'name' => isset( $nav_menu['name'] ) ? $nav_menu['name'] : $nav_menu_location,
+					'name' => $nav_menu['name'] ?? $nav_menu_location,
 				)
 			);
 			$this->pending_starter_content_settings_ids[] = $nav_menu_setting_id;
@@ -5240,10 +5240,10 @@ public function register_controls() {
 					'label'         => __( 'Logo' ),
 					'section'       => 'title_tagline',
 					'priority'      => 8,
-					'height'        => isset( $custom_logo_args[0]['height'] ) ? $custom_logo_args[0]['height'] : null,
-					'width'         => isset( $custom_logo_args[0]['width'] ) ? $custom_logo_args[0]['width'] : null,
-					'flex_height'   => isset( $custom_logo_args[0]['flex-height'] ) ? $custom_logo_args[0]['flex-height'] : null,
-					'flex_width'    => isset( $custom_logo_args[0]['flex-width'] ) ? $custom_logo_args[0]['flex-width'] : null,
+					'height'        => $custom_logo_args[0]['height'] ?? null,
+					'width'         => $custom_logo_args[0]['width'] ?? null,
+					'flex_height'   => $custom_logo_args[0]['flex-height'] ?? null,
+					'flex_width'    => $custom_logo_args[0]['flex-width'] ?? null,
 					'button_labels' => array(
 						'select'       => __( 'Select logo' ),
 						'change'       => __( 'Change logo' ),
diff --git a/src/wp-includes/class-wp-http-requests-response.php b/src/wp-includes/class-wp-http-requests-response.php
index 8032c54d875a7..c27a3053f2183 100644
--- a/src/wp-includes/class-wp-http-requests-response.php
+++ b/src/wp-includes/class-wp-http-requests-response.php
@@ -164,10 +164,10 @@ public function get_cookies() {
 				array(
 					'name'      => $cookie->name,
 					'value'     => urldecode( $cookie->value ),
-					'expires'   => isset( $cookie->attributes['expires'] ) ? $cookie->attributes['expires'] : null,
-					'path'      => isset( $cookie->attributes['path'] ) ? $cookie->attributes['path'] : null,
-					'domain'    => isset( $cookie->attributes['domain'] ) ? $cookie->attributes['domain'] : null,
-					'host_only' => isset( $cookie->flags['host-only'] ) ? $cookie->flags['host-only'] : null,
+					'expires'   => $cookie->attributes['expires'] ?? null,
+					'path'      => $cookie->attributes['path'] ?? null,
+					'domain'    => $cookie->attributes['domain'] ?? null,
+					'host_only' => $cookie->flags['host-only'] ?? null,
 				)
 			);
 		}
diff --git a/src/wp-includes/class-wp-network-query.php b/src/wp-includes/class-wp-network-query.php
index d69f1a98ed81d..cf907ea9fb1e0 100644
--- a/src/wp-includes/class-wp-network-query.php
+++ b/src/wp-includes/class-wp-network-query.php
@@ -460,12 +460,12 @@ protected function get_network_ids() {
 		 */
 		$clauses = apply_filters_ref_array( 'networks_clauses', array( compact( $pieces ), &$this ) );
 
-		$fields  = isset( $clauses['fields'] ) ? $clauses['fields'] : '';
-		$join    = isset( $clauses['join'] ) ? $clauses['join'] : '';
-		$where   = isset( $clauses['where'] ) ? $clauses['where'] : '';
-		$orderby = isset( $clauses['orderby'] ) ? $clauses['orderby'] : '';
-		$limits  = isset( $clauses['limits'] ) ? $clauses['limits'] : '';
-		$groupby = isset( $clauses['groupby'] ) ? $clauses['groupby'] : '';
+		$fields  = $clauses['fields'] ?? '';
+		$join    = $clauses['join'] ?? '';
+		$where   = $clauses['where'] ?? '';
+		$orderby = $clauses['orderby'] ?? '';
+		$limits  = $clauses['limits'] ?? '';
+		$groupby = $clauses['groupby'] ?? '';
 
 		if ( $where ) {
 			$where = 'WHERE ' . $where;
diff --git a/src/wp-includes/class-wp-query.php b/src/wp-includes/class-wp-query.php
index 21127dc755f1c..7bf43157464a1 100644
--- a/src/wp-includes/class-wp-query.php
+++ b/src/wp-includes/class-wp-query.php
@@ -3016,13 +3016,13 @@ public function get_posts() {
 			 */
 			$clauses = (array) apply_filters_ref_array( 'posts_clauses', array( compact( $pieces ), &$this ) );
 
-			$where    = isset( $clauses['where'] ) ? $clauses['where'] : '';
-			$groupby  = isset( $clauses['groupby'] ) ? $clauses['groupby'] : '';
-			$join     = isset( $clauses['join'] ) ? $clauses['join'] : '';
-			$orderby  = isset( $clauses['orderby'] ) ? $clauses['orderby'] : '';
-			$distinct = isset( $clauses['distinct'] ) ? $clauses['distinct'] : '';
-			$fields   = isset( $clauses['fields'] ) ? $clauses['fields'] : '';
-			$limits   = isset( $clauses['limits'] ) ? $clauses['limits'] : '';
+			$where    = $clauses['where'] ?? '';
+			$groupby  = $clauses['groupby'] ?? '';
+			$join     = $clauses['join'] ?? '';
+			$orderby  = $clauses['orderby'] ?? '';
+			$distinct = $clauses['distinct'] ?? '';
+			$fields   = $clauses['fields'] ?? '';
+			$limits   = $clauses['limits'] ?? '';
 		}
 
 		/**
@@ -3150,13 +3150,13 @@ public function get_posts() {
 			 */
 			$clauses = (array) apply_filters_ref_array( 'posts_clauses_request', array( compact( $pieces ), &$this ) );
 
-			$where    = isset( $clauses['where'] ) ? $clauses['where'] : '';
-			$groupby  = isset( $clauses['groupby'] ) ? $clauses['groupby'] : '';
-			$join     = isset( $clauses['join'] ) ? $clauses['join'] : '';
-			$orderby  = isset( $clauses['orderby'] ) ? $clauses['orderby'] : '';
-			$distinct = isset( $clauses['distinct'] ) ? $clauses['distinct'] : '';
-			$fields   = isset( $clauses['fields'] ) ? $clauses['fields'] : '';
-			$limits   = isset( $clauses['limits'] ) ? $clauses['limits'] : '';
+			$where    = $clauses['where'] ?? '';
+			$groupby  = $clauses['groupby'] ?? '';
+			$join     = $clauses['join'] ?? '';
+			$orderby  = $clauses['orderby'] ?? '';
+			$distinct = $clauses['distinct'] ?? '';
+			$fields   = $clauses['fields'] ?? '';
+			$limits   = $clauses['limits'] ?? '';
 		}
 
 		if ( ! empty( $groupby ) ) {
diff --git a/src/wp-includes/class-wp-site-query.php b/src/wp-includes/class-wp-site-query.php
index 826bf76c784ad..9c163cddd3d38 100644
--- a/src/wp-includes/class-wp-site-query.php
+++ b/src/wp-includes/class-wp-site-query.php
@@ -674,12 +674,12 @@ protected function get_site_ids() {
 		 */
 		$clauses = apply_filters_ref_array( 'sites_clauses', array( compact( $pieces ), &$this ) );
 
-		$fields  = isset( $clauses['fields'] ) ? $clauses['fields'] : '';
-		$join    = isset( $clauses['join'] ) ? $clauses['join'] : '';
-		$where   = isset( $clauses['where'] ) ? $clauses['where'] : '';
-		$orderby = isset( $clauses['orderby'] ) ? $clauses['orderby'] : '';
-		$limits  = isset( $clauses['limits'] ) ? $clauses['limits'] : '';
-		$groupby = isset( $clauses['groupby'] ) ? $clauses['groupby'] : '';
+		$fields  = $clauses['fields'] ?? '';
+		$join    = $clauses['join'] ?? '';
+		$where   = $clauses['where'] ?? '';
+		$orderby = $clauses['orderby'] ?? '';
+		$limits  = $clauses['limits'] ?? '';
+		$groupby = $clauses['groupby'] ?? '';
 
 		if ( $where ) {
 			$where = 'WHERE ' . $where;
diff --git a/src/wp-includes/class-wp-term-query.php b/src/wp-includes/class-wp-term-query.php
index d680fd602cb5d..db8c93fd9bda2 100644
--- a/src/wp-includes/class-wp-term-query.php
+++ b/src/wp-includes/class-wp-term-query.php
@@ -730,13 +730,13 @@ public function get_terms() {
 		 */
 		$clauses = apply_filters( 'terms_clauses', compact( $pieces ), $taxonomies, $args );
 
-		$fields   = isset( $clauses['fields'] ) ? $clauses['fields'] : '';
-		$join     = isset( $clauses['join'] ) ? $clauses['join'] : '';
-		$where    = isset( $clauses['where'] ) ? $clauses['where'] : '';
-		$distinct = isset( $clauses['distinct'] ) ? $clauses['distinct'] : '';
-		$orderby  = isset( $clauses['orderby'] ) ? $clauses['orderby'] : '';
-		$order    = isset( $clauses['order'] ) ? $clauses['order'] : '';
-		$limits   = isset( $clauses['limits'] ) ? $clauses['limits'] : '';
+		$fields   = $clauses['fields'] ?? '';
+		$join     = $clauses['join'] ?? '';
+		$where    = $clauses['where'] ?? '';
+		$distinct = $clauses['distinct'] ?? '';
+		$orderby  = $clauses['orderby'] ?? '';
+		$order    = $clauses['order'] ?? '';
+		$limits   = $clauses['limits'] ?? '';
 
 		$fields_is_filtered = implode( ', ', $selects ) !== $fields;