Get file extension

file-extension.js

// methood 1
function getFileExtension(filename:string) {
    return filename.slice((filename.lastIndexOf(".") - 1 >>> 0) + 2);
}

// method 2
function getFileExtension(filename:string) {
    filename.substring(filename.lastIndexOf('.')+1);
}

file-name-without-extension.js

function getFileName(name:string){
  return name.replace(/\.[^/.]+$/, "");
}