diff --git src/wp-includes/ID3/module.audio.flac.php src/wp-includes/ID3/module.audio.flac.php
index 014061da94..5655a5df99 100644
--- src/wp-includes/ID3/module.audio.flac.php
+++ src/wp-includes/ID3/module.audio.flac.php
@@ -65,7 +65,7 @@ class getid3_flac extends getid3_handler
 				break;
 			}
 			if ($BlockLength < 1) {
-				if ($BlockTypeText != 'reserved') {
+				if ($BlockTypeText !== 'reserved') {
 					// probably supposed to be zero-length
 					$this->warning('METADATA_BLOCK_HEADER.BLOCK_LENGTH ('.$BlockTypeText.') at offset '.$BlockOffset.' is zero bytes');
 					continue;
@@ -82,7 +82,7 @@ class getid3_flac extends getid3_handler
 			$BlockTypeText_raw['block_type']      = $BlockType;
 			$BlockTypeText_raw['block_type_text'] = $BlockTypeText;
 			$BlockTypeText_raw['block_length']    = $BlockLength;
-			if ($BlockTypeText_raw['block_type'] != 0x06) { // do not read attachment data automatically
+			if ($BlockTypeText_raw['block_type'] !== 0x06) { // do not read attachment data automatically
 				$BlockTypeText_raw['block_data']  = $this->fread($BlockLength);
 			}
 
diff --git src/wp-includes/ID3/module.tag.apetag.php src/wp-includes/ID3/module.tag.apetag.php
index 1305cfb509..ba1c34ef63 100644
--- src/wp-includes/ID3/module.tag.apetag.php
+++ src/wp-includes/ID3/module.tag.apetag.php
@@ -69,7 +69,7 @@ class getid3_apetag extends getid3_handler
 		} else {
 
 			$this->fseek($this->overrideendoffset - $apetagheadersize);
-			if ($this->fread(8) == 'APETAGEX') {
+			if ($this->fread(8) === 'APETAGEX') {
 				$info['ape']['tag_offset_end'] = $this->overrideendoffset;
 			}
 
diff --git src/wp-includes/ID3/module.tag.id3v2.php src/wp-includes/ID3/module.tag.id3v2.php
index ec448be87b..ded91e54f0 100644
--- src/wp-includes/ID3/module.tag.id3v2.php
+++ src/wp-includes/ID3/module.tag.id3v2.php
@@ -60,7 +60,7 @@ class getid3_id3v2 extends getid3_handler
 
 		$this->fseek($this->StartingOffset);
 		$header = $this->fread(10);
-		if (substr($header, 0, 3) == 'ID3'  &&  strlen($header) == 10) {
+		if (substr($header, 0, 3) === 'ID3'  &&  strlen($header) === 10) {
 
 			$thisfile_id3v2['majorversion'] = ord($header[3]);
 			$thisfile_id3v2['minorversion'] = ord($header[4]);
@@ -186,7 +186,7 @@ class getid3_id3v2 extends getid3_handler
 					}
 					$extended_header_offset += $thisfile_id3v2['exthead']['padding_size'];
 
-				} elseif ($id3v2_majorversion == 4) {
+				} elseif ($id3v2_majorversion === 4) {
 
 					// v2.4 definition:
 					//Extended header size   4 * %0xxxxxxx // 28-bit synchsafe integer
@@ -246,7 +246,7 @@ class getid3_id3v2 extends getid3_handler
 						$thisfile_id3v2['exthead']['flags']['restrictions_text']['imgsize']  = $this->LookupExtendedHeaderRestrictionsImageSizeSize($thisfile_id3v2['exthead']['flags']['restrictions']['imgsize']);
 					}
 
-					if ($thisfile_id3v2['exthead']['length'] != $extended_header_offset) {
+					if ($thisfile_id3v2['exthead']['length'] !== $extended_header_offset) {
 						$this->warning('ID3v2.4 extended header length mismatch (expecting '.intval($thisfile_id3v2['exthead']['length']).', found '.intval($extended_header_offset).')');
 					}
 				}
@@ -263,7 +263,7 @@ class getid3_id3v2 extends getid3_handler
 					$thisfile_id3v2['padding']['length'] = strlen($framedata);
 					$thisfile_id3v2['padding']['valid']  = true;
 					for ($i = 0; $i < $thisfile_id3v2['padding']['length']; $i++) {
-						if ($framedata[$i] != "\x00") {
+						if ($framedata[$i] !== "\x00") {
 							$thisfile_id3v2['padding']['valid'] = false;
 							$thisfile_id3v2['padding']['errorpos'] = $thisfile_id3v2['padding']['start'] + $i;
 							$this->warning('Invalid ID3v2 padding found at offset '.$thisfile_id3v2['padding']['errorpos'].' (the remaining '.($thisfile_id3v2['padding']['length'] - $i).' bytes are considered invalid)');
@@ -276,7 +276,7 @@ class getid3_id3v2 extends getid3_handler
 				$frame_name   = null;
 				$frame_size   = null;
 				$frame_flags  = null;
-				if ($id3v2_majorversion == 2) {
+				if ($id3v2_majorversion === 2) {
 					// Frame ID  $xx xx xx (three characters)
 					// Size      $xx xx xx (24-bit integer)
 					// Flags     $xx xx
@@ -307,7 +307,7 @@ class getid3_id3v2 extends getid3_handler
 						$nextFrameID = substr($framedata, $frame_size, 4);
 						if ($this->IsValidID3v2FrameName($nextFrameID, $id3v2_majorversion)) {
 							// next frame is OK
-						} elseif (($frame_name == "\x00".'MP3') || ($frame_name == "\x00\x00".'MP') || ($frame_name == ' MP3') || ($frame_name == 'MP3e')) {
+						} elseif (($frame_name === "\x00".'MP3') || ($frame_name === "\x00\x00".'MP') || ($frame_name === ' MP3') || ($frame_name === 'MP3e')) {
 							// MP3ext known broken frames - "ok" for the purposes of this test
 						} elseif (($id3v2_majorversion == 4) && ($this->IsValidID3v2FrameName(substr($framedata, getid3_lib::BigEndian2Int(substr($frame_header, 4, 4), 0), 4), 3))) {
 							$this->warning('ID3v2 tag written as ID3v2.4, but with non-synchsafe integers (ID3v2.3 style). Older versions of (Helium2; iTunes) are known culprits of this. Tag has been parsed as ID3v2.3');
@@ -320,7 +320,7 @@ class getid3_id3v2 extends getid3_handler
 					$frame_flags = getid3_lib::BigEndian2Int(substr($frame_header, 8, 2));
 				}
 
-				if ((($id3v2_majorversion == 2) && ($frame_name == "\x00\x00\x00")) || ($frame_name == "\x00\x00\x00\x00")) {
+				if ((($id3v2_majorversion === 2) && ($frame_name === "\x00\x00\x00")) || ($frame_name === "\x00\x00\x00\x00")) {
 					// padding encountered
 
 					$thisfile_id3v2['padding']['start']  = $framedataoffset;
@@ -329,7 +329,7 @@ class getid3_id3v2 extends getid3_handler
 
 					$len = strlen($framedata);
 					for ($i = 0; $i < $len; $i++) {
-						if ($framedata[$i] != "\x00") {
+						if ($framedata[$i] !== "\x00") {
 							$thisfile_id3v2['padding']['valid'] = false;
 							$thisfile_id3v2['padding']['errorpos'] = $thisfile_id3v2['padding']['start'] + $i;
 							$this->warning('Invalid ID3v2 padding found at offset '.$thisfile_id3v2['padding']['errorpos'].' (the remaining '.($thisfile_id3v2['padding']['length'] - $i).' bytes are considered invalid)');
@@ -435,7 +435,7 @@ class getid3_id3v2 extends getid3_handler
 
 		if (isset($thisfile_id3v2_flags['isfooter']) && $thisfile_id3v2_flags['isfooter']) {
 			$footer = $this->fread(10);
-			if (substr($footer, 0, 3) == '3DI') {
+			if (substr($footer, 0, 3) === '3DI') {
 				$thisfile_id3v2['footer'] = true;
 				$thisfile_id3v2['majorversion_footer'] = ord($footer[3]);
 				$thisfile_id3v2['minorversion_footer'] = ord($footer[4]);
@@ -633,7 +633,7 @@ class getid3_id3v2 extends getid3_handler
 		}
 
 		if (!empty($parsedFrame['flags']['DataLengthIndicator'])) {
-			if ($parsedFrame['data_length_indicator'] != strlen($parsedFrame['data'])) {
+			if ($parsedFrame['data_length_indicator'] !== strlen($parsedFrame['data'])) {
 				$this->warning('ID3v2 frame "'.$parsedFrame['frame_name'].'" should be '.$parsedFrame['data_length_indicator'].' bytes long according to DataLengthIndicator, but found '.strlen($parsedFrame['data']).' bytes of data');
 			}
 		}
@@ -651,8 +651,8 @@ class getid3_id3v2 extends getid3_handler
 			}
 			$this->warning($warning);
 
-		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] == 'UFID')) || // 4.1   UFID Unique file identifier
-			(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] == 'UFI'))) {  // 4.1   UFI  Unique file identifier
+		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] === 'UFID')) || // 4.1   UFID Unique file identifier
+			(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] === 'UFI'))) {  // 4.1   UFI  Unique file identifier
 			//   There may be more than one 'UFID' frame in a tag,
 			//   but only one with the same 'Owner identifier'.
 			// <Header for 'Unique file identifier', ID: 'UFID'>
@@ -662,8 +662,8 @@ class getid3_id3v2 extends getid3_handler
 			$parsedFrame['ownerid'] = (isset($exploded[0]) ? $exploded[0] : '');
 			$parsedFrame['data']    = (isset($exploded[1]) ? $exploded[1] : '');
 
-		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] == 'TXXX')) || // 4.2.2 TXXX User defined text information frame
-				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] == 'TXX'))) {    // 4.2.2 TXX  User defined text information frame
+		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] === 'TXXX')) || // 4.2.2 TXXX User defined text information frame
+				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] === 'TXX'))) {    // 4.2.2 TXX  User defined text information frame
 			//   There may be more than one 'TXXX' frame in each tag,
 			//   but only one with the same description.
 			// <Header for 'User defined text information frame', ID: 'TXXX'>
@@ -701,7 +701,7 @@ class getid3_id3v2 extends getid3_handler
 			//unset($parsedFrame['data']); do not unset, may be needed elsewhere, e.g. for replaygain
 
 
-		} elseif ($parsedFrame['frame_name'][0] == 'T') { // 4.2. T??[?] Text information frame
+		} elseif ($parsedFrame['frame_name'][0] === 'T') { // 4.2. T??[?] Text information frame
 			//   There may only be one text information frame of its kind in an tag.
 			// <Header for 'Text information frame', ID: 'T000' - 'TZZZ',
 			// excluding 'TXXX' described in 4.2.6.>
@@ -754,8 +754,8 @@ class getid3_id3v2 extends getid3_handler
 				unset($string, $wordsize, $i, $Txxx_elements, $Txxx_element, $Txxx_elements_start_offset);
 			}
 
-		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] == 'WXXX')) || // 4.3.2 WXXX User defined URL link frame
-				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] == 'WXX'))) {    // 4.3.2 WXX  User defined URL link frame
+		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] === 'WXXX')) || // 4.3.2 WXXX User defined URL link frame
+				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] === 'WXX'))) {    // 4.3.2 WXX  User defined URL link frame
 			//   There may be more than one 'WXXX' frame in each tag,
 			//   but only one with the same description
 			// <Header for 'User defined URL link frame', ID: 'WXXX'>
@@ -787,7 +787,7 @@ class getid3_id3v2 extends getid3_handler
 			unset($parsedFrame['data']);
 
 
-		} elseif ($parsedFrame['frame_name'][0] == 'W') { // 4.3. W??? URL link frames
+		} elseif ($parsedFrame['frame_name'][0] === 'W') { // 4.3. W??? URL link frames
 			//   There may only be one URL link frame of its kind in a tag,
 			//   except when stated otherwise in the frame description
 			// <Header for 'URL link frame', ID: 'W000' - 'WZZZ', excluding 'WXXX'
@@ -801,8 +801,8 @@ class getid3_id3v2 extends getid3_handler
 			unset($parsedFrame['data']);
 
 
-		} elseif ((($id3v2_majorversion == 3) && ($parsedFrame['frame_name'] == 'IPLS')) || // 4.4  IPLS Involved people list (ID3v2.3 only)
-				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] == 'IPL'))) {     // 4.4  IPL  Involved people list (ID3v2.2 only)
+		} elseif ((($id3v2_majorversion == 3) && ($parsedFrame['frame_name'] === 'IPLS')) || // 4.4  IPLS Involved people list (ID3v2.3 only)
+				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] === 'IPL'))) {     // 4.4  IPL  Involved people list (ID3v2.2 only)
 			// http://id3.org/id3v2.3.0#sec4.4
 			//   There may only be one 'IPL' frame in each tag
 			// <Header for 'User defined URL link frame', ID: 'IPL'>
@@ -881,8 +881,8 @@ class getid3_id3v2 extends getid3_handler
 			}
 
 
-		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] == 'MCDI')) || // 4.4   MCDI Music CD identifier
-				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] == 'MCI'))) {     // 4.5   MCI  Music CD identifier
+		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] === 'MCDI')) || // 4.4   MCDI Music CD identifier
+				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] === 'MCI'))) {     // 4.5   MCI  Music CD identifier
 			//   There may only be one 'MCDI' frame in each tag
 			// <Header for 'Music CD identifier', ID: 'MCDI'>
 			// CD TOC                <binary data>
@@ -892,8 +892,8 @@ class getid3_id3v2 extends getid3_handler
 			}
 
 
-		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] == 'ETCO')) || // 4.5   ETCO Event timing codes
-				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] == 'ETC'))) {     // 4.6   ETC  Event timing codes
+		} elseif ((($id3v2_majorversion >= 3) && ($parsedFrame['frame_name'] === 'ETCO')) || // 4.5   ETCO Event timing codes
+				(($id3v2_majorversion == 2) && ($parsedFrame['frame_name'] === 'ETC'))) {     // 4.6   ETC  Event timing codes
 			//   There may only be one 'ETCO' frame in each tag
 			// <Header for 'Event timing codes', ID: 'ETCO'>
 			// Time stamp format    $xx
diff --git src/wp-includes/comment-template.php src/wp-includes/comment-template.php
index d125f0c2dd..7bba06ba55 100644
--- src/wp-includes/comment-template.php
+++ src/wp-includes/comment-template.php
@@ -552,7 +552,7 @@ function get_comment_class( $css_class = '', $comment_id = null, $post = null )
 	++$comment_alt;
 
 	// Alt for top-level comments.
-	if ( 1 == $comment_depth ) {
+	if ( 1 === $comment_depth ) {
 		if ( $comment_thread_alt % 2 ) {
 			$classes[] = 'thread-odd';
 			$classes[] = 'thread-alt';
