I am trying to extract a string from within a larger string where it get everything inbetween a :
and a ;
Current
Str = 'MyLongString:StringIWant;'
Desired Output
newStr = 'StringIWant'
You can try this
var mySubString = str.substring(
str.lastIndexOf(":") + 1,
str.lastIndexOf(";")
);