IndexOF is not working in Flow Designer

[Community Alums]

HI Team,

I am getting below error while returning value in Flow Designer. Below is the code:

I am getting below error:

 Cannot find function indexOf in object .,Detail: Cannot find function indexOf in object

[Community Alums]

Issue is resolved its working now  after changing 

line no 4 to String.

var arrValues = fd_data._3__for_each.item.u_authority_role.toString();