Jquery select elements, select fixed child elements under the same class, only the index values of father and child, how to choose to child

<div class="father">
     <div class="child">child1</div>
     <div class="child">child2</div>
     <div class="child">child3</div>
     <div class="child">child4</div>
 </div>
  <div class="father">
     <div class="child">child1</div>
     <div class="child">child2</div>
     <div class="child">child3</div>
     <div class="child">child4</div>
 </div>
  <div class="father">
     <div class="child">child1</div>
     <div class="child">child2</div>
     <div class="child">child3</div>
     <div class="child">child4</div>
 </div>
Html
Mar.31,2021
Is that what

means? 

  
 nth-of-type

Previous: Use spark or hadoop to delete duplicate two-way relational data

Next: How to download the file stream returned through the background of ajax API in JS? Ask for help

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
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-64f5-1b38927-2b978.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b38927-2b978.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?