如何从JavaScript的插入位置获取最后的信息？

Question

I am using pure JavaScript and I want to get the last word where my current caret position is from the text string in a variable as shown in the below image, I want to get the unknown word.

In C#, I used the below code concept and its working there perfectly...

private static char[] splitters = new char[] { ' ', '\n', '۔' };
int caretPosition = string.SelectionStart;
string tempLastWord = string.Substring(0, caretPosition);
string lastWord = tempLastWord.Substring(tempLastWord.LastIndexOfAny(splitters) + 1);

Now I want to do the same in the pure JavaScript as below...

var splitters =  [ ' ', '\n', '۔' ];
var caretPosition = document.getElementById(Desired_ID).value.slice(0, document.getElementById(Desired_ID).selectionStart).length;
var tempLastWord = document.getElementById(Desired_ID).value.substring(0, caretPosition);
var lastWord = tempLastWord.substring(tempLastWord.lastIndexOf(splitters) + 1);

But my JavaScript code is not working perfectly. Can anyone help me...???

Answer 1

var lastWord = tempLastWord.substring(tempLastWord.lastIndexOf('\n') + 1);
lastWord = lastWord.substring(lastWord.lastIndexOf(' ') + 1);
lastWord = lastWord.substring(lastWord.lastIndexOf('?') + 1);

This works.

Answer 2

var lastWord = tempLastWord.substring（tempLastWord.lastIndexOf（splitters + 1））;