Why regular judgment should be made by adding class method to JavaScript Native

hasClass function what is the purpose here

Mar.20,2021

means that if the element already has this class, don't add it again.

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b39e8d-2c1d7.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b39e8d-2c1d7.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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