how to set fileupload file in javascript code example

Example 1: File Upload Button and display file javascript

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form>
  <label for="file-upload" class="custom-file-upload">
    <i class="fa fa-cloud-upload"></i> Upload Image
  </label>
  <input id="file-upload" name='upload_cont_img' type="file" style="display:none;">
</form>

Example 2: get file extension file upload control in javascript

function getFile(filePath) {
        return filePath.substr(filePath.lastIndexOf('\\') + 1).split('.')[0];
    }

    function getoutput() {
        outputfile.value = getFile(inputfile.value);
        extension.value = inputfile.value.split('.')[1];
    }

Example 3: File Upload Button and display file javascript

.custom-file-upload {
  border: 1px solid #ccc;
  display: inline-block;
  padding: 6px 12px;
  cursor: pointer;
}

Example 4: get file extension file upload control in javascript

<input id='inputfile' type='file' name='inputfile' onChange='getoutput()'><br>
    Output Filename <input id='outputfile' type='text' name='outputfile'><br>
    Extension <input id='extension' type='text' name='extension'>