How to access element index when passing list of elements in ".to" or ".from" etc

[sak]

This code doesn't work as the 'index' variable is not defined, what is the best way to go about it?
 

timeline.from([...featureCards], {

      opacity: 0,

      y: 60 * Math.pow(-1, index),

      ease: "power3.out",

      duration: 0.7,

      stagger: 0.3,

    });

[sak]

My bad, figured it out from the docs - 

timeline.from([...featureCards], {

      opacity: 0,

      y: (idx) => 60 * Math.pow(-1, idx),

      ease: "power3.out",

      duration: 0.7,

      stagger: 0.3,

    });