How to write this statement into javascript?

Question

Hello,

How to write this statement into java script

This code writing in c# now i am implemented in java script

 

string strTemp=124:1000;3200;12555;

 int ind = strTemp.Length - 1;

 strTemp = strTemp.Substring(0, ind - 1);

Thanks & Regards,

Brijesh Mandaliya