In SharePoint 2013, when creating a custom display template for an item, sometimes you need to know, which item in the whole search results list it is. In other words, you need the information of which item in the whole sequence that is, and perform your own logic according to the parameter.
I’ve looked for the property quite a while, but finally found it. It is called piSearchResultId.
Practically you can call it like that in your display template:
It’s value is similar to the following:
0_1 for first item in the list
1_1 for the second item
2_1 for the third item
…and so forth.
With such values you can extract the first number, and there you go!
Hope this helps,