Answers for "how to get extension from file name javascript"

javascript get file extension

var fileName = "myDocument.pdf";
var fileExtension = fileName.split('.').pop(); //"pdf"

how to get the extension from filename using javascript

var ext = fileName.substr(fileName.lastIndexOf('.') + 1);

how to get file extension in javascript

var fileName = "myDocument.pdf";
var fileExtension = fileName.split('.').pop(); //"pdf"

javascript - get the filename and extension from input type=file

//Use lastIndexOf to get the last \ as an index and use substr to get the remaining string starting from the last index of \


function getFileNameWithExt(event) {

  if (!event || !event.target || !event.target.files || event.target.files.length === 0) {
    return;
  }

  const name = event.target.files[0].name;
  const lastDot = name.lastIndexOf('.');

  const fileName = name.substring(0, lastDot);
  const ext = name.substring(lastDot + 1);

  outputfile.value = fileName;
  extension.value = ext;
  
}
<input id='inputfile' type='file' name='inputfile' onChange='getFileNameWithExt(event)'><br>
  Output Filename <input id='outputfile' type='text' name='outputfile'><br>
  Extension <input id='extension' type='text' name='extension'>