Document name without file extension [via script]

@Ciccillotto 

You should be able to find examples of this on the forum in any script that saves files, as it is common to strip the filename extension from the current format to replace it with another one when saving in a different format.

The most flexible and elegant method is via a regular expression find/replace (works with single or multiple period characters):

var dName = activeDocument.name.replace(/\.[^\.]+$/, '');
alert(dName);

Another simpler method is via a split/remove on the period character, retaining the characters on the left (presuming a "clean" filename with only a single period character):

var dName = activeDocument.name.split('.')[0];
alert(dName);

If there are multiple period characters in the filename, presume that the last period is the extension:

var extensionIndex = activeDocument.name.lastIndexOf(".");
if (extensionIndex != -1) {
    var dName = activeDocument.name.substr(0, extensionIndex);
    alert(dName);
} else {
    alert(activeDocument.name);
}

https://gist.github.com/MarshySwamp/40aefebb39e0eef2d7599ac4050490d9