How to extract extension from filename string in Javascript

Question

how would i get the File extension of the file in a variable  like if I have a file as 1 txt I need the txt part of it

User · Answer

This is the solution if your file has more    dots  in the name    lt script type  text javascript  gt var x    file1 asdf txt   var y   x split       alert y  y length -1    lt  script gt

User · Answer

Use the lastIndexOf method to find the last period in the string  and get the part of the string after that   var ext   fileName substr fileName lastIndexOf        1

User · Answer

I would recommend using lastIndexOf   as opposed to indexOf    var myString    this is my file txt  alert myString substring myString lastIndexOf      1

User · Answer

var x    1 txt   alert  x substring x indexOf      1      note 1  this will not work if the filename is of the form file example txt note 2  this will fail if the filename is of the form file

User · Answer

Better to use the following  Works always   var ext    fileName split      pop      This will return the extension without a dot prefix  You can add       ext to check against the extensions you wish to support

User · Answer

I use code below   var fileSplit   filename split       var fileExt       if  fileSplit length  gt  1    fileExt   fileSplit fileSplit length - 1      return fileExt

User · Answer

get the value in the variable  amp  then separate its extension just like this   var find file ext document getElementById  filename   value  var file ext          exec find file ext      This will help you

User · Answer

Try this  May solve your problem   var file name string    file name string png   var file name array   file name string split       var file extension   file name array file name array length - 1     Regards

User · Answer

A variant that works with all of the following inputs     file name with dots txt   file txt   file     null undefined   would be   var re                       var ext   re exec  file name with dots txt   1         txt  var ext   re exec  file txt   1                        txt  var ext   re exec  file   1                           undefined var ext   re exec     1                               undefined var ext   re exec null  1                             undefined var ext   re exec undefined  1                        undefined   Explanation                 begin non-capturing group                 a dot                 begin capturing group  captures the actual extension                    anything except a dot  multiple times                 end capturing group               end non-capturing group  make it optional               anchor to the end of the string

User · Answer

I personally prefer to split the string by   and just return the last array element     var fileExt   filename split      pop     If there is no   in filename you get the entire string back   Examples    some value                                      gt   some value    htaccess                                       gt   htaccess      images something cool jpg                    gt   jpg   http   www w3schools com jsref jsref pop asp    gt   asp   http   stackoverflow com questions 680929       gt   com questions 680929

[javascript] How to extract extension from filename string in Javascript?

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